White House lawyers on Saturday began presenting their defense of President Donald Trump at his historic Senate impeachment trial, saying the president had done nothing wrong in his dealings with Ukraine and accusing Democrats of seeking to overturn the results of the 2016 election.

White House counsel Pat Cipollone took the floor for opening arguments at a rare weekend session of the 100-member Senate, which will decide whether the 45th US president should be removed from office.

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

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

In an initial response to the president’s being charged, written by Cipollone and Sekulow, the defense said that the articles of impeachment — passed by the majority-Democrat House of Representatives — “are a dangerous attack on the right of the American people to freely choose their president.”

Last week, 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.

McConnell has said he won’t consider the witness issue until after the arguments and questioning take place, and his majority means he will likely prevail.

On January 22, 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.

House prosecutors spent the previous three days laying out a detailed case that Trump withheld military aid to Ukraine to pressure his Ukrainian counterpart to open an investigation into political rival Joe Biden.

Cipollone said Democrats were asking the Senate to “overturn the results of the last election” and remove Trump from the ballot in the upcoming November vote.

“They’re asking you to do something that no Senate has ever done,” the White House counsel said.

“They’re asking you to tear up all of the ballots across this country,” he said. “Take that decision away from the American people.

“They are here to perpetrate the most massive interference in an election in American history and we can’t allow that to happen.”

Shortly before the defense began its presentation, Trump fired off a tweet with insulting nicknames for leading Democrats and told his supporters to tune in to the live television broadcast.

The Republican president also tweeted remarks from supporters lauding his achievements since taking office in January 2017.

Trump’s lawyers will have 24 hours spread over three days to present their defense of the president to the Senate, where Republicans hold a 53 to 47 seat majority.

They plan to speak for up to three hours on Saturday and resume their presentation on Monday.

The short session will be welcome to four senators battling for the Democratic presidential nomination, allowing them to return to the campaign trail ahead of the February 3 caucuses in Iowa, which kick off the primary season.

Vermont Senator Bernie Sanders, Massachusetts Senator Elizabeth Warren, Minnesota Senator Amy Klobuchar and Colorado Senator Michael Bennet have been forced to remain in Washington for the hearings.

A two-thirds majority, or 67 senators, is required to remove a president from office and Democrats do not appear to have made any inroads in Trump’s wall of Republican support.

Earlier, house impeachment manager Adam Schiff called dramatically for the Senate to remove President Donald Trump from and said that the US leader cannot be trusted to put the country’s interests ahead of his own.

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.

Democrats are hoping their arguments will at least persuade some Republicans, who hold a 53-47 majority in the Senate, to support their call to issue subpoenas next week for four top current and former Trump aides to testify, and for internal White House records about the Ukraine affair.

(With inputs from agency)