Top Republicans doubt the whistleblower whose complaint prompted impeachment proceedings is truly willing to be questioned by both parties, despite the whistleblower’s attorney announcing an offer to do so on Sunday morning.

Mark Zaid, the whistleblower’s attorney, announced that he had contacted Democratic California Rep. Devin Nunes to notify him that the whistleblower would accept written questions from Republicans on the House Intelligence Committee.

Zaid told CBS on Saturday night that his client wants to be as bipartisan as possible throughout this process while remaining anonymous. The attorney noted that accepting written questions will allow the whistleblower to protect his or her identity from Republicans, who have asked that the whistleblower be identified.

Republicans, however, saw this as a ploy to put up a bipartisan front on the Sunday television shows without any expectation to follow through.

Senior Republicans told the Washington Examiner they did not receive Zaid’s request until Sunday morning, claiming it’s not a sincere attempt by the whistleblower to answer questions but rather a political stunt. One top House Republican called the move by the whistleblower’s lawyer a “Sunday narrative ambush” timed for the morning public affairs shows in a bid to shape public opinion.

California Rep. Kevin McCarthy highlighted this on Face the Nation, claiming he wasn’t made aware of such an offer until hearing about it on air.

"I have never received that offer, and I'm the lead Republican," he said, noting that Nunes is based in California and hadn’t notified him of any letter as of Sunday morning.

Republicans have criticized Democrats for their handling of the impeachment process so far, as much of it has been behind closed doors without the ability for the GOP to call witnesses.

David M. Drucker contributed to this report.