Key Republican is working with 'small group' of GOP senators to ensure witnesses at Trump's Senate trial

Sen. Susan Collins (R-Maine), one of the Republican Party's most moderate lawmakers, confirmed Friday that she is working with a "fairly small group" of Republican senators to ensure that witnesses will be called at President Donald Trump's impeachment trial.

"We should be completely open to calling witnesses," she said, the Bangor Daily News reported.

Collins said both Trump's lawyers and House impeachment managers should be allowed to call witnesses in the upcoming trial.

However, Collins, who is up for re-election later this year, declined to say how many Republicans are included in the discussions.

Senate Majority Leader Mitch McConnell (R-Ky.), who said last month that he is working in "total cooperation" with the White House in the trial, has indicated that he will follow the trial model used during former President Bill Clinton's impeachment trial, NBC News reported.

From NBC News:

In that case, the two sides made opening arguments and took questions from senators before there was a motion to either dismiss the case or hear from witnesses. In the Clinton case, the motion to dismiss failed, and senators wound up taking videotaped depositions of three witnesses, portions of which were played at the trial.

Collins has criticized McConnell for his apparent lack of impartiality.

Democrats begin impeachment trial negotiations by sending McConnell a partial list of witnesses they sought to call, including John Bolton and Mick Mulvaney, the acting White House chief of staff. McConnell, however, quickly dismissed the requests.

Bolton, however, said this week that he would testify if called upon.

It is not yet clear when Trump's impeachment trial will begin, though it could start as early as next week.

House Speaker Nancy Pelosi ended her stalemate with Republicans on Friday, announcing that she would transfer two articles of impeachment — one for abuse of power and another for obstruction of Congress — to the Senate next week.