Trump whistleblower willing to take written questions from Republicans under 'penalty of perjury'

A lawyer for the whistleblower who raised alarms about President Donald Trump's dealings with Ukraine said Sunday (local time) his client is willing to answer written questions submitted by House Republicans.

The surprise offer, made to Rep Devin Nunes, the top Republican on the House Intelligence Committee, would allow Republicans to ask questions of the whistleblower, who spurred the Democratic-led impeachment inquiry, without having to go through the committee's chairman, Rep Adam Schiff, D-Calif.

Attorney Mark Zaid tweeted that the whistleblower would answer questions directly from Republican members "in writing, under oath & penalty of perjury", part of a bid to stem efforts by Mr Trump and his GOP allies to unmask the person's identity. Only queries seeking the person's identity won't be answered, he said.

"Being a whistleblower is not a partisan job nor is impeachment an objective. That is not our role," Mr Zaid tweeted.

"So we have offered to @DevinNunes.

"We will ensure timely answers," he said.

Rep Nunes' office did not have immediate comment.

The offer comes as Mr Trump has repeatedly demanded the release of the whistleblower's identity, tweeting Sunday that the person "must come forward".

The whistleblower raised concerns about Mr Trump's July 25 call with Ukrainian President Volodymyr Zelenskiy, in which he pressed Mr Zelenskiy to investigate Mr Trump's political rivals. That call became the catalyst for the impeachment inquiry.

"Reveal the Whistleblower and end the Impeachment Hoax!" Mr Trump wrote.

House Minority Leader Kevin McCarthy, R-Calif., said Sunday that he had not yet discussed the whistleblower's offer with Rep Nunes, but stressed that the person should answer questions in a public appearance before the committee.

"When you're talking about the removal of the president of the United States, undoing democracy, undoing what the American public had voted for, I think that individual should come before the committee," Mr McCarthy told CBS' "Face the Nation".

"We need an openness that people understand this," he added.

Republicans view a political opportunity in unmasking the CIA official, who the intelligence community's inspector general said could have "arguable political bias".

The inspector general nevertheless found the whistleblower's complaint to be "credible".

Mr Zaid said his team had addressed the issue of alleged bias with Republican members of the committee and had stressed the need for anonymity to maintain the safety of the whistleblower and that person's family, "but with little effect in halting the attacks".

"Let me be absolutely clear: our willingness to cooperate has not changed," tweeted Andrew P. Bakaj, another attorney representing the whistleblower.

"What we object to and find offensive, however, is the effort to uncover the identity of the whistleblower."

Mr Bakaj wrote on Saturday that "their fixation on exposing the whistleblower's identity is simply because they're at a loss as to how to address the investigations the underlying disclosure prompted".

The whistleblower's secondhand account of the call has been providing a road map for House Democrats investigating whether the president and others in his orbit pressured Ukraine to probe political opponents, including former Vice President Joe Biden.

US whistleblower laws exist to protect the identity and careers of people who bring forward accusations of wrongdoing by government officials. Lawmakers in both parties have historically backed those protections.

The Associated Press typically does not reveal the identity of whistleblowers.