Donald Trump

Twenty years after leading the impeachment efforts against Bill Clinton, Ken Starr made his debut on the Senate floor in defence of Donald Trump, while two Republican senators admit that John Bolton's testimony is becoming "increasingly likely" following bombshell revelations in the former national security chief's book.

The president reacted angrily after the manuscript Mr Bolton's book was leaked in which the former aide claims the president told him the decision to withhold military assistance to Ukraine last summer was explicitly tied to demands for an investigation into Joe Biden.

"If John Bolton said this, it was only to sell a book," Mr Trump tweeted, arguing that the House should have subpoenaed Mr Bolton when it was gathering evidence in November (it did), prompting impeachment manager Adam Schiff to say the revelation "blasts another hole" in his counsel's defence.

Senator Mitt Romney said Mr Bolton's revelations are "relevant" and that he would like to hear them on the Senate floor.

Susan Collins of Maine echoed Mr Romney's concerns and said that Mr Bolton's claims "strengthen the case for witnesses and have prompted a number of conversations among my colleagues".

All the president's lawyers: The team fighting Trump's impeachment Show all 6 1 /6 All the president's lawyers: The team fighting Trump's impeachment All the president's lawyers: The team fighting Trump's impeachment Alan Dershowitz Dershowitz is a controversial American lawyer best known for the high-profile clients he has successfully defended. Those clients have included OJ Simpson, Jeffrey Epstein and Harvey Weinstein. One longtime Harvard Law associated told the New Yorker Dershowitz "revels in taking positions that ultimately are not just controversial but pretty close to indefensible." Getty All the president's lawyers: The team fighting Trump's impeachment Ken Starr Starr became a household name in the 1990s as the independent counsel who led the investigation that led to Bill Clinton's impeachment. That investigation began as a look into a real estate scandal known as Whitewater, and eventually led to impeachment after Mr Clinton lied under oath about having an affair with White House intern Monica Lewinsky. AP All the president's lawyers: The team fighting Trump's impeachment Jay Sekulow Sekulow is the president's longtime personal attorney, and, now, personal lawyer in the White House. He has been accused by former Rudy Giuliani associate Lev Parnas of being "in the loop" during the Ukraine scandal. Getty All the president's lawyers: The team fighting Trump's impeachment Pam Bondi Bondi is the former attorney general in Florida, and a longtime backer of the president's. She made a name for herself in Florida for taking hyper partisan stances on issues, and her penchant for publicity. She is likely to be a prominent public-facing figure during the trial. AFP/Getty All the president's lawyers: The team fighting Trump's impeachment Pat Cipollone Cipollone is the White House counsel, and leading the president's defence team. Getty All the president's lawyers: The team fighting Trump's impeachment Rudy Giuliani While not officially named as one of the president's impeachment lawyers, it is hard to ignore Giuliani's outsized role in this process. The former mayor of New York has been making headlines for months as he defends his client, and for his apparent role in the effort to compel Ukraine to launch the investigation into Joe Biden. We'll see how he figures in the actual trial, which he has said he would like to be a part of. Reuters

Mr Starr was widely criticised for his defence and accused of contradicting his own arguments he made as a prosecutor. He derided the impeachment of Mr Trump over a lack of bipartisan support and claimed that the president was afforded executive privilege allowing him to withhold documents and testimony from subpoenas.

The president's defence also attacked Joe Biden and his son Hunter for what they argued was his corrupt role on the board of Ukrainian energy company Burisma.

Meanwhile, Fox host Chris Wallace railed against a contributor he told to "get your facts straight" on air as the talking heads squabbled over the admission of evidence in the Clinton trial compared to the Trump proceedings.

Back at the White House, Mr Trump hosted Israeli prime minister Benjamin Netanyahu and his opposition counterpart Benny Gantz for briefing on his plans to bring peace to the Middle East.

The president intends to announce those plans on Tuesday amid widespread criticism and calls for boycotts from Palestinians, who have largely been ignored from US-led discussions over the region's future.