Washington CNN  — 

Former White House chief of staff John Kelly said Friday if there are no witness testimonies in the Senate impeachment trial of President Donald Trump that it is considered “a job only half done.”

“If I was advising the United States Senate, I would say, ‘If you don’t respond to 75 percent of the American voters and have witnesses, it’s a job only half done,’” Kelly told NJ Advance Media in an interview published Friday. “You open yourself up forever as a Senate that shirks its responsibilities.”

The Senate is poised to defeat a motion to seek witnesses and documents, signaling the impeachment trial could be nearing an end. Alaska Sen. Lisa Murkowski, the last true publicly undecided Republican senator, said Friday she would oppose witnesses. Murkowski and Sen. Lamar Alexander, a Tennessee Republican, were potential swing votes on whether the Senate should seek out witnesses, like former national security adviser John Bolton, and ultimately decided against it.

Kelly told NJ Advance Media that Bolton was “a copious note taker” and “an honest guy and an honorable guy.”

Kelly said earlier this week he believes Bolton’s allegation that Trump told Bolton that US security aid to Ukraine was conditioned on an investigation of Trump’s political rivals. Bolton’s allegations, contained in a draft manuscript first reported by The New York Times, led to calls from Democrats for Bolton to testify in Trump’s impeachment trial. The allegations added uncertainty to a vote to determine whether the Senate should subpoena for witnesses and documents.

A source with direct knowledge of the manuscript has told CNN the Times’ telling of Bolton’s account is accurate. The President, though, has denied claims he told Bolton aid to Ukraine was tied to an investigation of Joe and Hunter Biden. Trump asked Bolton to resign in September and said he strongly disagreed with many of Bolton’s suggestions.

Democratic Rep. Adam Schiff took Kelly’s statement a step further, saying Friday afternoon on the Senate floor, “The President’s former chief of staff, General Kelly, said a senate trial without witnesses is ‘a job only half done.’ A trial without witnesses is only ‘half a trial.’ Well, I have to say, I can’t agree. A trial without witnesses is no trial at all.”

“You either have a trial or you don’t, and if you’re going to have a real trial, you need to hear from the people who have firsthand information,” Schiff, the lead House impeachment manager, said.

CNN’s Kaitlan Collins and Chandelis Duster contributed to this report.