WASHINGTON, United States (AP) — Democratic House prosecutors launched their final arguments Friday at Donald Trump’s impeachment trial arguing the president will persist in abusing the power of his office ahead of the 2020 election unless Congress intervenes to remove him from office.

“He is who he is,” Representative Adam Schiff, the chairman of the House Intelligence Committee, told senators, accusing Trump of putting the US-Ukraine relationship on the line in a way that benefited Russia just so he could take a political “cheap shot” at Joe Biden.

“You cannot leave a man like that in office,” Schiff said. “You know it’s not going to stop. It’s not going to stop unless the Congress does something about it.”

As Democrats pressed their case before sceptical Republican senators for a third day, the president’s legal team was preparing for his defence, expected to start Saturday. Trump, eyes on the audience beyond the Senate chamber, bemoaned the schedule in a tweet, saying “looks like my lawyers will be forced to start on Saturday, which is called Death Valley in TV”.

The Senate jurors faced another long day Friday armed with pens and paper — and, for Republicans, the gift of fidget spinners — for the historic trial.

The president is being tried in the Senate after the House impeached him last month, accusing him of abusing his office by asking Ukraine for politically motivated probes of political foe Biden and Biden’s son while withholding military aid from a US ally that was at war with bordering Russia. The second article of impeachment accuses him of obstructing Congress by refusing to turn over documents or allow officials to testify in the House probe.