Democratic impeachment managers called Saturday for President Donald Trump’s conviction, calling him a threat to national security in a legal brief filed ahead of the start of the senate trial coming week and the White House shot back accusing Democrats of launching a “brazen” and “unlawful” attempt to overturn his election in 2016.

“The evidence overwhelmingly establishes that he is guilty of both,” the managers wrote in a 111-page brief referring to the two articles of impeachment charging him with abuse of power and obstruction of congress. “The only remaining question is whether the members of the Senate will accept and carry out the responsibility placed on them by the Framers of our Constitution and their constitutional oaths.”

The weekend exchange between the two sides in the first legal filings set the tone for the bitter political fight that is expected at the trial that starts Tuesday to determine if the president should be removed from office, following his impeachment by the House of Representatives on December 18, or be allowed to stay.

President Trump’s legal team has until Monday noon to file their legal brief. But it responded to the Democratic brief with a scathing six-page statement. They said the articles of impeachment were a “brazen and unlawful attempt to overturn the results of the 2016 election and interfere with the 2020 election”.

The Democratic-led House impeached Trump last December accusing him of abusing the powers of his office to force Ukraine to investigate his political rivals with an eye on the 2020 elections, and then obstructing congress’s investigation into it by blocking officials from answering subpoenas to testify and refusing to release documents.