US President Donald Trump’s legal team argued forcefully against the relevance of testimony from John Bolton as they concluded their impeachment trial defence and the Senate braced for debate on whether to summon Trump’s former national security adviser and other witnesses into the trial.

“This should end now, as quickly as possible,” White House counsel Pat Cipollone declared, capping a defence presentation that painted Trump as a victim and took dismissive swipes at Bolton, the potential witness who has scrambled Republican hopes for a swift end to the trial.

A day after the defence team largely brushed past Bolton, attorney Jay Sekulow addressed the controversy head-on by dismissing his manuscript – said to contradict a key defence argument about Trump’s dealings with Ukraine – as “inadmissible.” The argument was meant to dissuade Republicans from pursuing witnesses including Bolton, who writes in a forthcoming book that Trump told him he wanted to withhold military aid from Ukraine until it helped with investigations into Democratic rival Joe Biden.

“It is not a game of leaks and unsourced manuscripts,” Sekulow said.

The argument built on a separate one Monday night from Trump attorney Alan Dershowitz, who said that nothing in the manuscript – even if true – rises to the level of an impeachable offence. Sekulow also sought to undermine the credibility of Bolton’s book by noting that Attorney General William Barr has disputed comments attributed to him by Bolton.

The legal team, in hours of arguments, delved into areas that Democrats see as outside the scope of impeachment, alleging law enforcement bias and seizing on surveillance errors the FBI has acknowledged making in its Russian election interference probe.

Trump’s attorneys also argued that the Founding Fathers took care to make sure that impeachment was narrowly defined, with offences clearly enumerated.

“The bar for impeachment cannot be set this low,” Sekulow said. “Danger. Danger. Danger. These articles must be rejected. The Constitution requires it. Justice demands it.”

The case now moves toward written questions, with senators on both sides getting 16 hours to pose queries. By late in the week, they are expected to hold a vote on whether or not to hear from any witnesses.

While scoffing at the manuscript, Trump and the Republicans have strongly resisted summoning Bolton to testify in person about what he saw and heard as Trump’s top national security adviser.

Senate Republicans spent two days behind closed doors discussing ideas to satisfy those who want to hear more testimony without prolonging the proceedings -or jeopardising the president’s expected acquittal.

The ideas appear to be losing steam as quickly as they emerge.

One Republican, Senator James Lankford of Oklahoma, was floating an idea backed by Senator Lindsey Graham to subpoena Bolton’s book manuscript so senators can see the evidence themselves – in private.

However, Chuck Schumer, the Senate’s top Democrat, called the proposal, which would keep Bolton out of public testimony, “absurd.”

“We’re not bargaining with them. We want four witnesses, and four sets of documents, then the truth will come out,” Schumer said.