This article is more than 7 months old

This article is more than 7 months old

Donald Trump’s legal team has delivered a fiery response to impeachment summons from the Senate, calling the two articles passed by the House “a dangerous attack on the right of the American people to freely choose their president”.

Impeachment: is Trump set to survive and win a second term? Read more

“This is a brazen and unlawful attempt to overturn the results of the 2016 election and interfere with the 2020 election, now just months away,” the lawyers said on Saturday, also claiming the charges against the president were invalid as they did not concern a crime.

Impeachment is a political process, not a criminal one. Under the US constitution, the president can be removed if found guilty of whatever lawmakers consider to be “high crimes and misdemeanours”. Trump is charged with abusing his power and obstructing Congress.

On Saturday, House impeachment managers outlined their view of the case against Trump in a 111-page legal brief of their own. It pulls together private and public testimony of a dozen witnesses, ambassadors and national security officials at high levels of government.

In a joint statement, the seven managers led by the Democratic intelligence committee chair Adam Schiff said their case was “simple, the facts are indisputable, and the evidence is overwhelming: President Trump abused the power of his office to solicit foreign interference in our elections for his own personal political gain, thereby jeopardising our national security, the integrity of our elections, and our democracy”.

“And when the president got caught, he tried to cover it up by obstructing the House’s investigation into his misconduct.”

Trump’s legal team, led by White House counsel Pat Cipollone and Trump personal lawyer Jay Sekulow, is challenging the impeachment on both procedural and constitutional grounds, claiming Trump has been mistreated by House Democrats and that he did nothing wrong.

Trump will file a more detailed legal brief on Monday, and the House will be able to respond to the Trump filing on Tuesday.

The case hinges on a 25 July phone call with Ukrainian leader Volodymyr Zelenskiy, in which Trump asked his counterpart to do him a “favour” and investigate both a conspiracy theory concerning election interference and ties between former vice-president Joe Biden and his son, Hunter Biden, and the eastern European country.

Biden remains a possible Democratic candidate for president. At the time of the Ukraine call, Trump was withholding from Kyiv nearly $400m of military aid and the prospect of a White House meeting for Zelenskiy.

Trump’s legal team for the Senate trial, starting on Tuesday,will also include Ken Starr, whose investigation led to the impeachment of Bill Clinton, and former Harvard professor, Alan Dershowitz.

Both have been fixtures on Fox News. Some in the administration have echoed warnings from Senate majority leader Mitch McConnell that the lawyers must be sensitive to staid Senate traditions and not use the sharp rhetoric exhibited during House proceedings last year.

Many observers suggest the slow nature of the trial will prove a turnoff to the American public, boosting Trump’s hopes of surviving unscathed. Others report that the president wants to add fire and TV knowhow to the team mounting his defence.

White House lawyers succeeded in blocking Trump from adding House Republicans to his team, the AP reported, but also advised against picking Dershowitz. They are concerned about the professor’s association with Jeffrey Epstein, the financier who killed himself in a New York jail last summer while awaiting trial on sex trafficking charges.

Dershowitz has said he will deliver constitutional arguments defending Trump from allegations he abused his power and obstructed Congress.

Former New York mayor and current Trump lawyer Rudy Giuliani told the AP the president had a “top-notch” team and insisted he was not disappointed to be excluded. Giuliani, who many in the White House blame for leading Trump to impeachment over Ukraine, said his focus would be on being a potential witness.

On Friday, House Democrats released documents, text messages, audio recordings and photos turned over by Lev Parnas, a Giuliani associate indicted on campaign finance charges. The release included photos of the Soviet-born businessman posing with Giuliani, Trump and Donald Trump Jr.

Facebook Twitter Pinterest Rudy Giuliani, left, with Lev Parnas at the Trump Hotel in Washington in September. Photograph: Reuters Staff/Reuters

Messages between Parnas and a staffer for Devin Nunes, a congressman and Trump ally, were also released. Parnas appeared to be connecting the staffer to Ukrainian officials who pushed unfounded corruption allegations against the Bidens.

The documents also raised more questions about the security of Marie Yovanovitch, a former ambassador to Ukraine who testified in House impeachment proceedings. An unidentified individual with a Belgian country code appeared to describe Yovanovitch’s movements.

The document release followed the announcement by the Government Accountability Office that the White House violated federal law by withholding congressionally approved security aid.

Trump’s is the third impeachment in US history and no case has been stronger | Jonathan Freedland Read more

The White House said it did not have to follow decisions by the GAO because it is an arm of Congress. White House officials noted that Trump did send the aid to Kyiv.

But the GAO report and Parnas documents intensified the pressure senators have been under to call more witnesses for the trial. The White House has instructed officials to disregard subpoenas seeking testimony or information.

On Saturday Lisa Murkowski of Alaska, a moderate Republican wooed by Democrats, told reporters she was comfortable waiting to decide if more information was needed until after hearing arguments from House managers and attorneys for Trump and questions from other senators.

Trump seems certain to survive the Senate trial, as a two-thirds majority will be needed to convict and remove him and Republicans remain in line behind him.

In their statement on Saturday, the House impeachment managers said senators “must accept and fulfill the responsibility placed on them by the framers of our constitution and the oaths they have just taken to do impartial justice. They must conduct a fair trial – fair to the president and fair to the American people”.