Former Rep. Beto O’Rourke (D-Texas) hit back at his fellow 2020 Democratic presidential candidate South Bend, Ind., Mayor Pete ButtigiegPeter (Pete) Paul ButtigiegTrump hits Fox News's Chris Wallace over Ukraine coverage Sanders can gain ground by zeroing in on corruption Biden praises Buttigieg for criticizing GOP attacks: 'That's a good man' MORE over their diverging stances on the merits of a gun buyback program.

O'Rourke had hit Buttigieg earlier this month over the mayor's hesitancy to back a mandatory buyback program for assault rifles.

In an interview on Monday, Buttigieg responded to O’Rourke’s criticism, saying the former Texas congressman was just looking to make headlines.

“I get it. He needs to pick a fight in order to stay relevant,” Buttigieg said in an interview with Snapchat’s “Good Luck America.”

O’Rourke responded, quote-tweeting the interview along with a new jab.

“Pete can belittle the grassroots; he can call buybacks a 'shiny object.' He can say whatever he wants, but guns kill 40,000 people each year,” O’Rourke tweeted. “Those people deserve action. I’ll be fighting for them.”

Pete can belittle the grassroots; he can call buybacks a “shiny object.” He can say whatever he wants, but guns kill 40,000 people each year.

Those people deserve action. I’ll be fighting for them. https://t.co/yZwbyfSngr

Beto O'RourkeBeto O'RourkeButtigieg pushes back on O'Rourke threat to strip religious institutions of tax-exempt status O'Rourke raises .5 million in third quarter Conservatives slam Beto O'Rourke over threat to tax-exempt status for religious organizations MORE (@BetoORourke) October 14, 2019

Other Democratic presidential candidates were quick to pile on Buttigieg as well, with Sens. Cory BookerCory Anthony BookerRepublicans wrestle with impeachment strategy O'Rourke campaign says path to victory hinges on top 5 finishes in Iowa, Nevada O'Rourke raises .5 million in third quarter MORE (D-N.J.) and Kamala HarrisKamala Devi HarrisRepublicans wrestle with impeachment strategy Klobuchar takes shots at health and education plans supported by Sanders and Warren Kamala Harris to Trump Jr.: 'You wouldn't know a joke if one raised you' MORE (D-Calif.) also tweeting their displeasure with his comments.

“Leaving more than 5 million assault weapons on the street isn't a ban, it's a Band-Aid,” Harris tweeted in response to Buttigieg calling mandatory gun buybacks “confiscation.”

Leaving more than 5 million assault weapons on the street isn't a ban, it's a Band-Aid. https://t.co/LuAbJAwOZh

— Kamala Harris (@KamalaHarris) October 14, 2019

Meanwhile, Booker said that Buttigieg calling gun buyback programs "confiscation" is "doing the NRA's work for them," adding that the National Rifle Association doesn't "need our help."

Calling buyback programs "confiscation" is doing the NRA's work for them, @PeteButtigieg—and they don't need our help. https://t.co/eshiBU7PIg

— Cory Booker (@CoryBooker) October 14, 2019

Buttigieg has released a plan to address gun violence that calls for universal background checks, the implementation of a "red flag" gun law, and a ban on the sales of assault weapons and high-capacity magazines.

O’Rourke has been a vocal supporter of mandatory buybacks since a mass shooting rocked his hometown of El Paso, Texas. He was praised by his fellow candidates at the last Democratic debate for his response to the shooting.

Buttigieg, O'Rourke, Booker and Harris are all expected to take the debate stage alongside eight others on Tuesday night.