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In the wake of a new report about the contents of former National Security Adviser John Bolton's forthcoming book about his time working with President Trump, the seven House impeachment managers are calling for him to testify in the Senate impeachment trial.

The New York Times reported on Sunday that in the unpublished manuscript, Bolton writes that Trump told him he wanted to withhold military aid to Ukraine until officials there launched investigations into former Vice President Joe Biden and his son Hunter. Trump has publicly denied that is the reason he froze the money, which was finally released in September, the same month Bolton left his position as national security adviser. Bolton sent the manuscript to close associates and the White House for review, the Times said.

In a joint statement, the Democratic impeachment managers called the report "explosive" and urged the Republican-controlled Senate to call Bolton as a witness during the trial. "The Senate trial must seek the full truth and Mr. Bolton has vital information to provide," the managers said. "There is no defensible reason to wait until his book is published, when the information he has to offer is critical to the most important decision senators must now make — whether to convict the president of impeachable offenses."

The Senate is expected to vote later this week on whether to call witnesses during the trial. Bolton, who complied with a blanket White House ban on testifying during the House impeachment inquiry, has said if he is subpoenaed, he will testify. "The odds of deposition for new witnesses is certainly rising dramatically," a senior GOP official told The Washington Post on Sunday night.