UPDATE 2-Top Republican in Senate launches harsh attack on 'toxic' impeachment

The top Republican in the U.S. Senate on Thursday harshly attacked Democratic lawmakers a day after they impeached President Donald Trump, sending the strongest signal yet that the Senate will not remove Trump from office. Senate Majority Leader Mitch McConnell accused Democrats in the House of Representatives of succumbing to "transient passions and factionalism" when they voted on Wednesday to impeach Trump on charges of abuse of power and obstruction of Congress.

Trump, only the third U.S. president to be impeached, is likely to go on trial in the Senate early in January on the charges related to his attempts to pressure Ukraine to investigate Democratic political foe Joe Biden. Dismissing the impeachment vote as "toxic" and "slapdash," McConnell made it clear that he did not think the Republican-run Senate should find Trump guilty. "The vote did not reflect what had been proven. It only reflects how they feel about the president. The Senate must put this right," McConnell said on the Senate floor.

"It could not be clearer which outcome would serve the stabilizing, institution-preserving, fever-breaking role for which the United States Senate was created," he said. McConnell did not elaborate but he has already said he is working in tandem with the White House ahead of a Senate trial, drawing accusations from Democrats that he is ignoring his duty to consider the evidence in an impartial manner.

Representative Steny Hoyer, the No. 2 House Democrat, said on MSNBC that Democrats were concerned McConnell may not allow a full trial. "It's very hard to believe that Mitch McConnell can raise his right hand and pledge to be impartial," Hoyer said.

Trump, 73, is accused of abusing his power by pressuring Ukraine to investigate Biden, a former U.S. vice president, as well as a discredited theory that Democrats conspired with Ukraine to meddle in the 2016 election. Democrats said Trump held back $391 million in security aid for Ukraine and a coveted White House meeting for Ukrainian President Volodymyr Zelenskiy as leverage to coerce Kiev into interfering in the 2020 election by smearing Biden.

It was unclear on Thursday how or when a trial in the Senate would play out after House Speaker Nancy Pelosi said she might delay sending over the articles of impeachment to the Senate in order to pressure that chamber to conduct what she viewed as a fair trial. (Additional reporting by Patricia Zengerle, Amanda Becker, Susan Heavey, Richard Cowan, and Lisa Lambert; Writing by Alistair Bell; Editing by Andy Sullivan and Sonya Hepinstall)