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"Why is this less credible than the whistleblower when this is direct knowledge and the whistleblower is hearsay?" Giuliani asked in the ABC interview.

Shokin alleges that he was "staunchly politically unaffiliated" and that then-President of Ukraine Petro Poroshenko ordered him to resign due to pressure from Joe Biden who was threatening to withhold $1 billion in subsidies to Ukraine "until I was removed from office."

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Shokin says: "The truth is that I was forced out because I was leading a wide-ranging corruption probe into Burisma Holdings…a natural gas firm active in Ukraine. Joe Biden’s son, Hunter Biden, was a member of the Board of Directors. I presume Burisma, which was connected with gas extraction, had the support of the US Vice President Joe Biden because his son was on the Board of Directors."

The Biden campaign responded later Sunday afternoon with a letter to TV networks including ABC, CBS, NBC, CNN, and Fox News to "demand" that Rudy Giuliani no longer be allowed on the air.

"We are writing today with grave concern that you continue to book Rudy Giuliani on your air to spread false, debunked conspiracy theories on behalf of Donald Trump," Biden campaign advisers Anita Dunn and Kate Bedingfield wrote in the letter, according to the New York Times. "Giving Rudy Giuliani valuable time on your air to push these lies in the first place is a disservice to your audience and a disservice to journalism."

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"I have an affidavit here that's been online for six months that nobody bothered to read from the gentleman who was fired, Viktor Shokin, the so-called corrupt prosecutor," Rudy Giuliani told ABC's George Stephanopoulos on Sunday. "The Biden people say that he wasn't investigating Hunter Biden at the time. He says under oath that he was."

Giuliani said he didn't start out "investigating Joe Biden," but he "fell upon Joe Biden in investigating how the Ukrainians were conspiring with the Hillary Clinton campaign to turn over dirty information, including something for which a Ukrainian has already been convicted. So I have a very solid basis for doing it."

"I am defending my client the best way I know how. This is not about getting Joe Biden in trouble, this is about proving that Donald Trump was framed by the Democrats," Giuliani declared.

Later in the interview, Giuliani asked Stephanopoulos: "George, I'm being respectful, is it possible for you to ever treat a charge against a Democrat in the same way you treat a charge against a Republican? Are you telling me that if there was a sworn affidavit, and the names here were Donald Trump and Donald Trump Jr., you, your network, the entire Washington -- wherever they are -- I wouldn't have to be sitting here show it to you."

Giuliani continued: "I also know, if Obama had called Biden in when The New York Times first broke the story in December of 2015 that his son had a massive conflict of interest working for the most corrupt oligarch in Ukraine -- if Obama had called him in, like a president who understood Article II, section 3, and said: Joe what the heck are you doing with your son, who just got tossed out of the military, where I had to pull strings to get him in, his son is working for the biggest crook in Ukraine and we're trying to fix corruption in Ukraine and you've got him working for Mykola Zlochevsky, who stole $5 billion... Did Obama do that? Did Obama do that?"

Full transcript:

GIULIANI: Did I ever ask the Chinese government [for information about Biden]? No. If I did that, you could truly say I was investigating Joe Biden. I'm not investigating Joe Biden.

I fell upon Joe Biden in investigating how the Ukrainians were conspiring with the Hillary Clinton campaign to turn over dirty information, including something for which a Ukrainian has already been convicted. So I have a very solid basis for doing it.

I also support everything I say with affidavits. I have an affidavit here that's been online for six months that nobody bothered to read from the gentleman who was fired, Viktor Shokin, the so-called corrupt prosecutor.

The Biden people say that he wasn't investigating Hunter Biden at the time. He says under oath that he was.

STEPHANOPOULOS: But, as you know -- I know he says that under oath.

(CROSSTALK)

GIULIANI: Oh, he must not be -- we don't even know him. He must not be telling the truth.

STEPHANOPOULOS: We know that Vice President Biden was part of an international effort, was part of a government-wide effort to help push the prosecutor out because of allegations of corruption.

GIULIANI: If the name here was Donald Trump and Donald Trump Jr., and it said that: "The president of the Ukraine asked me to resign due to pressure from the U.S. presidential administration. The truth is that I was forced out because I was leading a wide-ranging corruption -- corruption -- corruption probe into Burisma Holdings and Joe Biden's son."

That's under oath by the prosecutor who was handling the case, who they say is corrupt. Now, a lot of prosecutors...

STEPHANOPOULOS: It's not just they who have said he's corrupt. The European Union has said he's corrupt. The entire U.S. administration said he's corrupt.

GIULIANI: Oh, they all said it. Anybody prove it?

STEPHANOPOULOS: That's why he was removed from office.

GIULIANI: No, it wasn't. The reason he was removed was because the president forced him to resign. And then, just in case we want to deal with corruption thing, I have another affidavit. This time from another Ukrainian prosecutor who says that the day after Biden strong-armed the president to remove Shulkin, they show up in the prosecutor's office -- lawyers for Hunter Biden show up in the prosecutor's office and they give an apology for the dissemination of false information.

You know -- you know what the apology is for? For having -- having gotten out the story that this guy was corrupt. Now, if you met this guy, he's not very good at corruption because he's very poor.

Unlike the prosecutor who tanked the case on Biden, who's driving around in a Bentley.

STEPHANOPOULOS: OK, you -- you've gotten those charges out there. Let's talk about --

GIULIANI: No, no, I haven't gotten them out there.

STEPHANOPOULOS: But you have gotten them out there.

GIULIANI: No, I haven't.

STEPHANOPOULOS: You're just -- those affidavits --

GIULIANI: Can I make a contrast? Can I just make a slight contrast with the so-called whistleblower? The whistleblower says I don't have any direct knowledge, I just heard things. Up until two weeks before he did that, that wouldn't even been a complaint. Would have been dismissed.

STEPHANOPOULOS: Those are from -- he heard things from White House officials --

GIULIANI: He heard a lot of stuff.

STEPHANOPOULOS: -- and everything in that -- that he said about the phone call is basically tracks --

GIULIANI: No it isn't.

STEPHANOPOULOS: -- the transcript that was revealed -- released by the --

GIULIANI: No -- you know what he's wrong about? He says about the phone call that my meeting with -- with Mr. Yermak was a direct result of the phone call. No it wasn't. The meeting was set up three days before the phone call. It wasn't a direct result of the phone call. He said -- he heard from numerous military people that I attempted to contact two individuals, Andre Bolden (ph) and a fellow named Kananov (ph). Simple fact is I never did, it's a total lie. I never would have contacted Andre Bolden (ph) because I had been told by very, very good authorities that he's corrupt.

STEPHANOPOULOS: You said earlier --

GIULIANI: And I shouldn't go near him. He said about five other things that are totally false.

STEPHANOPOULOS: And this -- well, this is -- this is what the investigation will be about (ph).

GIULIANI: And I'm not saying he was false, I'm saying he could have heard it wrong.

STEPHANOPOULOS: This --

GIULIANI: That's why -- George, that's why it's hearsay. Because it's unreliable.

STEPHANOPOULOS: And that's what the investigation is about (ph) --

GIULIANI: -- unlike him --

(CROSSTALK)

GIULIANI: -- unlike him -- please, can I just make my point?

STEPHANOPOULOS: You've been making your point.

GIULIANI: No I haven't. Unlike him. These are affidavits.

STEPHANOPOULOS: From individuals who are implicated and who have been -- and who --

GIULIANI: Isn't that the way we prosecute crime? People implicated?

STEPHANOPOULOS: Well, this -- that will be part of the investigation but the House --

(CROSSTALK)

GIULIANI: How about if I -- how about if I tell you over the next week four more of these will come out from four other prosecutors?

STEPHANOPOULOS: They will -- and they will all be investigated. Meantime --

GIULIANI: No, no, no, George, they won't be because they've been online for six months and the Washington press will not accept the fact that Joe Biden may have done something like this.

STEPHANOPOULOS: If these are so serious --

GIULIANI: If this was Donald Trump and Donald Trump Jr., I wouldn't be here (ph) having to do this.

STEPHANOPOULOS: Mr. Mayor --

GIULIANI: I am defending my client the best way I know how. This is not about getting Joe Biden in trouble, this is about proving that Donald Trump was framed by the Democrats.

STEPHANOPOULOS: If these charges are so serious and so credible, why have they not been picked up by the president's hand-picked FBI director, the president's hand-picked attorney general, William Barr?

GIULIANI: That's a -- that's a good question.

STEPHANOPOULOS: What's the answer to that?

GIULIANI: I don't know. Maybe they have been. I don't know if they have been or they haven't. Or -- and if I did, I couldn't tell you.

STEPHANOPOULOS: But isn't that the appropriate place for it, if they are serious and credible charges, rather than the president --

(CROSSTALK)

GIULIANI: One of the ways this came to me is that the four different Ukrainian prosecutors -- you can dismiss them all. I can't, if they're willing to swear under oath -- tell me that they tried to get it to the FBI and the Justice Department for an entire year and were completely --

STEPHANOPOULOS: But this is the -- the president picked the head of the FBI, the president picked the head of the Justice Department. If they're serious, if they're credible --

GIULIANI: Well William Barr wasn't at the Justice Department when this -- when this --

STEPHANOPOULOS: He's there now.

GIULIANI: Well, I'm not telling you whether they are or aren't investigating it. I'm telling you -- look, I got this a long time ago, in November of 2018, very serious concerns at that time by the Ukrainian prosecutors about the FBI. So I decided to go another way. Also because if I went to the FBI or I went to the Justice Department --

STEPHANOPOULOS: You've never done that?

GIULIANI: I'm not saying I did or I didn't but if I did it at that time --

STEPHANOPOULOS: But what's the answer? Did you or didn't you?

GIULIANI: I have never gone -- I've never initiated going to them. For a simple reason. Schiff would claim I was exercising my influence to get it investigated. So here's what I did. I put it online. I announced it. I went on ever place and said I have this evidence, and I waited for them to come and get it on their own. So I didn't get a charge that I was trying to force an investigation they didn't want to do. But if you just bother to Google, I made it easy to make this case --

STEPHANOPOULOS: Mr. Mayor, I've -- I've -- I've gone through this scenario --

GIULIANI: Have you read Kalyanuk's (ph) statement?

STEPHANOPOULOS: -- I -- I have read -- I have read affidavits on both sides --

GIULIANI: Mr. Kalyanuk (ph) is another prosecutor --

STEPHANOPOULOS: -- I have -- I have seen that there's no credible allegation of wrongdoing against Joe Biden --

(CROSSTALK)

GIULIANI: Why is this less credible than the whistleblower when this is -- this is direct knowledge and the whistleblower is hearsay? Why is Kalyanuk's (ph) statement not credible evidence when he went under oath? Why isn't Kulyuk's (ph) statement not credible evidence when he went under oath?

STEPHANOPOULOS: You'll have to ask that to the Ukrainian authorities and our own Justice Department, which is not prosecuting it. But I do -- I -- I do have to move on on this. Do you -- do you --

GIULIANI: Who says our -- our Justice Department isn't prosecuting it?

STEPHANOPOULOS: You believe the Justice Department is investigating?

GIULIANI: I don't know. If they're not, it would be kind of surprising.

STEPHANOPOULOS: There is no evidence that they are.

But are you going to cooperate with a House investigation?

GIULIANI: George, is it possible -- excuse me, I'm being respectful -- is it possible for you to ever treat a charge against a Democrat in the same way you treat a charge against a Republican? Are you telling me that if there was a sworn affidavit, and the names here were Donald Trump and Donald Trump Jr., you, your network, the entire Washington -- wherever they are -- I wouldn't have to be sitting here show it to you.

STEPHANOPOULOS: Are you telling me if there was evidence that Barack Obama was calling up the Russians and say I want you to look into Donald Trump that wouldn't be blowing that up?

GIULIANI: He didn't do that.

STEPHANOPOULOS: I know he didn't.

GIULIANI: No, no, no. Trump didn't do that. He called them up and he said I want you to investigate these charges of corruption. If he hadn't asked them to investigate Biden, he would have violated the Article II, section 3 of the constitution.

And I also know, if Obama had called Biden in when The New York Times first broke the story in December of 2015 that his son had a massive conflict of interest working for the most corrupt oligarch in Russia -- in Ukraine -- if Obama had called him in, like a president who understood Article II, section 3, and said Joe what the heck are you doing with your son, who just got tossed out of the military, where I had to pull strings to get him in, his son is working for the biggest crook -- listen to me, the biggest crook in Ukraine and we're trying to fix corruption in Ukraine and you've got him working for Mykola Zlochevsky, who stole $5 billion...

STEPHANOPOULOS: Mr. Mayor, you made your case.

GIULIANI: Did Obama do that? Did Obama do that?

STEPHANOPOULOS: Are you going to cooperate with the House Intelligence Committee?

GIULIANI: That is a question that has a lot, a lot of implications to it. Believe it or not, I'm an attorney. Everything I did was to defend my client. I am proud of what I did. And I am proud of having uncovered what will turn out to be a massive pay for play scheme, not unlike the Clinton Foundation.

STEPHANOPOULOS: So will you cooperate?

GIULIANI: And then we've got to look at the $1.5 billion from China and the two other places...

STEPHANOPOULOS: And yet you keep on throwing out the charges...

GIULIANI: And the two other places that Hunter Biden went to sell his father's office.

STEPHANOPOULOS: Will you cooperate with the House Intelligence Committee?

GIULIANI: I wouldn't cooperate with Adam Schiff. I think Adam Schiff should be removed. If they remove Adam Schiff, if they put a neutral person in, who hasn't pre-judged the case, if they put someone in, a Democrat who hasn't expressed an opinion yet -- if I had a judge in the case and he had already announced I'm going to impeach, if he already went ahead and did a whole false episode, wouldn't I move to recuse that judge.

STEPHANOPOULOS: So that's your answer, you're not going to cooperate?

GIULIANI: I didn't say that. I said I will considerate it.

STEPHANOPOULOS: You said you wouldn't do it. You said you will not cooperate with Adam Schiff.

GIULIANI: I said I will consider it. I have to be guided by my client, frankly. I'm a lawyer. It's his privilege, not mine. If he decides that he wants me to testify, of course I'll testify, even though I think Adam Schiff is an illegitimate chairman. He has already prejudged the case.

If we want fairness here, we've got to put somebody in charge of that committee who has an open mind, not someone who wants to hang the president, who said I have evidence of Russian collusion.

Adam wears the evidence. Why don't you ask him to produce the evidence.

STEPHANOPOULOS: He's coming up right now. Mayor, thanks for your time.

GIULIANI: Are you going to interrupt him as often as you interrupt me?

STEPHANOPOULOS: I gave you plenty of case to make your case this morning, Mr. Mayor.

GIULIANI: Let's see how the interview goes. Hi, Adam, nice to see you.

STEPHANOPOULOS: Thanks for coming on this morning.

GIULIANI: ...gee, how could they have to go after Joe Biden.

STEPHANOPOULOS: Thank you, Mr. Mayor.

GIULIANI: Oh my god, I'm going to kill the guy who did it.