The historic impeachment trial of US President Donald Trump opened with fireworks on Tuesday as Democrats angrily accused Senate Republicans of seeking a “cover-up” without witnesses or new evidence.

With the US leader facing potential removal from office for abuse of power, his close ally Mitch McConnell laid out ground rules that would block subpoenaing key witnesses or documents while each side makes its case — potentially crippling prosecutors’ arguments.

McConnell said, “The basic structure we’re proposing is just as eminently fair and even-handed”.

Adam Schiff, the leader of the House impeachment managers prosecuting Trump, countered that the process “makes no sense” for a trial, and was designed instead to ensure evidence is never heard and Trump is exculpated.

McConnell’s rules aim to make the case “go away as quickly as possible to cover up his misdeeds,” Schiff said in his opening presentation on the Senate floor.

On Tuesday, Trump arrived in Davos for the 2020 World Economic Forum, where he was scheduled to give a speech just hours before his impeachment trial kicks into high gear in Washington.

On December 18, President Trump was formally impeached in a historic vote in the House of Representatives.

On Wednesday, House Speaker Nancy Pelosi signed the articles of impeachment charging President Trump with abuse of power and obstruction of Congress which were delivered to the Senate.

The job of these lawmakers, sworn in last week as jurors, is to decide if Trump abused his office and obstructed Congress as charged in two articles of impeachment approved last month by the House of Representatives.

They state that Trump tried to pressure Ukraine into interfering in the 2020 US election to help him win, and then tried to thwart a congressional probe of his behaviour.

On Saturday, Trump’s legal team presented its line of defense for his impeachment probe, a process they dismissed as unconstitutional and “dangerous”.

On Monday, Senate Majority Leader Mitch McConnell proposed rules calling for each side to have 24 hours over two days to present their arguments which makes for long trial days stretching late into the night but is a significantly quicker pace than in Bill Clinton’s impeachment trial in 1999. The chamber will debate and vote on the proposed rules Tuesday.

On Friday, President Trump unexpectedly brought up the impeachment during a reception at the White House for the Louisiana State University football team four days after they were crowned national champions.

Pelosi argued that the president’s conduct when it came to Ukraine left Democrats with “no choice but to act,” charging that Trump abused the powers of the presidency and leaving little doubt that the House will hold a vote to impeach him as early as before Christmas.

In September, the impeachment inquiry, which Nancy Pelosi initiated over a complaint by an anonymous whistleblower, is looking into White House’s alleged efforts to withhold military aid to have Ukraine investigate a Trump’s political rival, Joe Biden.

(With inputs from agency)