The stakes over witness testimony at President Donald Trump’s impeachment trial are rising now that a draft of a book from former national security adviser John Bolton appears to undercut a key defence argumentIn an upcoming book, former national security adviser John Bolton reportedly writes that Trump told him that he wanted to withhold hundreds of millions of dollars in security aid from Ukraine until it helped him with politically charged investigations. he’s ‘prepared to testify’ in the Senate impeachment trial if subpoenaed. (Carolyn Kaster/Associated Press)The stakes over witness testimony at President Donald Trump’s impeachment trial are rising now that a draft of a book from former national security adviser John Bolton appears to undercut a key defence argument. Bolton writes in the forthcoming book that Trump told him that he wanted to withhold hundreds of millions of dollars in security aid from Ukraine until it helped him with politically charged investigations, including into Democratic rival Joe Biden. Trump’s legal team has repeatedly insisted that the president never tied the suspension of military assistance to the country to investigations that he wanted into Biden and his son.The account immediately gave Democrats new fuel in their pursuit of sworn testimony from Bolton and other witnesses, a question expected to be taken up later this week by the Republican-led Senate. The trial resumes Monday afternoon with arguments from Trump’s defence team. Bolton’s account was first reported by The bioreports and confirmed to The Associated Press by a person familiar with the manuscript on the condition of anonymity to discuss the book, The Room Where It Happened; A White House Memoir, ahead of its release March 17. …transcripts of my calls with President Zelensky are all the proof that is needed, in addition to the fact that President Zelensky & the Foreign Minister of Ukraine said there was no pressure and no problems. Additionally, I met with President Zelensky at the United Nations…—@realDonaldTrump When the Times report went online Sunday night, the seven House Democratic managers immediately called on all senators to insist that Bolton be called as a witness and provide his notes and other relevant documents. Sen. Chuck Schumer, the Senate’s top Democrat, issued the same call. Trump denied the claims in a series of tweets early Monday. “I NEVER told John Bolton that the aid to Ukraine was tied to investigations into Democrats, including the Bidens,” Trump said in a tweet. “In fact, he never complained about this at the time of his very public termination. If John Bolton said this, it was only to sell a book.” Trump said people could look at transcripts of his call, and statements by Ukraine President Vlodymyr Zelensky that there was no pressure for such investigations to get the aid. Bolton, who acrimoniously left the White House a day before Trump ultimately released the Ukraine aid on Sept. 11, has already told lawmakers that he is willing to testify, despite the president’s order barring aides from cooperating in the probe. “Americans know that a fair trial must include both the documents and witnesses blocked by the President — that starts with Mr. Bolton,” the impeachment managers said in a statement. First, though, Trump’s legal team will begin laying out its case in depth, turning to several high-profile attorneys to argue against impeachment. The lawyers revealed the broad outlines of their defence in a rare but truncated Saturday session, where they accused House Democrats of using the impeachment case to try to undo the results of the last presidential election and drive Trump from office. In this image from video, a graphic is displayed as impeachment manager Rep. Jerrold Nadler argues in favour of an amendment proposed by Senate Minority Leader Chuck Schumer to subpoena John Bolton during the impeachment trial against President Donald Trump in the Senate at the U.S. Capitol in Washington last Wednesday. (The Associated Press) The legal team is expected to pick up on that theme and also dive into areas that received negligible attention during the Democrats’ presentation, including the now-concluded investigation into ties between Russia and Trump’s 2016 campaign. Trump’s lawyers aren’t expected to take as much time for their arguments as the Democrats, whose impeachment managers spoke for about 24 hours over three days. But they also don’t need to: Acquittal is likely in a Senate where Republicans hold a 53-47 majority, with a two-thirds vote needed for conviction. Still, they see an opportunity to counter the allegations, defend the powers of the presidency and prevent Trump from being weakened politically ahead of November’s election. Trump faces two articles of impeachment. One accuses him of abusing his power by asking Ukraine to investigate Joe Biden, his Democratic rival, at the same time that his administration withheld hundreds of millions of dollars from the country. The other alleges that Trump obstructed Congress by directing aides to not cooperate with the impeachment inquiry. Rep. Adam Schiff, left, and Rep. Jerry Nadler lead some of their fellow House managers to the Senate floor on the third day of the impeachment trial of U.S. President Donald Trump in Washington. The managers are the Democratic legislators who are prosecuting the case. (Mary F. Calvert/Reuters) The legal team will portray Trump as having been harassed by investigations from federal agents — and Democrats — since he took office, and seize on the FBI’s recent acknowledgment of surveillance errors during the Russia probe. The lawyers have already hinted that they will focus attention on Biden just as he campaigns for a first-place finish in next week’s Iowa caucuses. Monday’s presentation is expected to include appearances by Alan Dershowitz, who will argue that impeachable offences require criminal-like conduct, and Ken Starr, the independent counsel in the Whitewater investigation that led to the impeachment of President Bill Clinton. Former Florida Attorney General Pam Bondi is also expected to make arguments. Lawyer Alan Dershowitz is part of U.S. President Donald Trump’s impeachment trial defence team. In this file photo, he’s pictured talking to the press outside federal court in New York in December 2019. (Richard Drew/The Associated Press) Democrats argued their side of the impeachment case for three days last week, warning that Trump will persist in abusing his power and endangering American democracy unless Congress intervenes to remove him before the 2020 election. On Saturday, the president’s attorneys said there was no evidence that Trump made the military aid contingent on the country announcing an investigation into Biden. They also accused Democrats of omitting information that was favourable to Trump’s case.