The White House said on Wednesday it would refuse to co-operate with the inquiry being led by House Democrats into whether the president should be removed from office – with lawyers rejecting the move as “baseless” and “constitutionally invalid”.
However public support continues to swing against Mr Trump – with the latest poll carried out for his preferred media network, Fox News, finding a majority believe he should no longer sit in the Oval Office.
In a survey of 1,003 voters across the US, 51 per cent said they thought he should be impeached, a rise on the previous month’s 42 per cent.
Only 43 per cent of respondents said the House of Representatives should not vote for his removal – with the most prominent reason given for opposing the action being that the president “did nothing wrong”.
The results of the poll also suggested the president’s messaging on Democratic rival Joe Biden and his son Hunter are not making an impact on the American public.
Mr Trump and his lawyer, Rudy Giuliani, have repeatedly implied the former vice-president pressured the government of Ukraine to sack the nation’s prosecutor general, who was investigating a company which had his son on the board.
The allegation, and whether or not the president pressured the eastern European government to investigate the claim, is at the centre of the move to remove Mr Trump from the White House.
However, respondents to the poll appeared to be indifferent to the alleged actions of Mr Biden. Asked how troubling they find the allegations against the former vice-president, 32 per cent said not at all – while only 19 per cent said they found the claims “extremely” troubling.
In turn, the majority of respondents - 38 per cent - said they found Mr Trump’s dealings with the Ukrainian president extremely troubling, compared to 26 per cent who said the situation was not troubling at all.
Meanwhile 66 per cent said it was not appropriate for the president to ask foreign leaders to investigate his rivals – compared to 25 per cent who said such actions would be appropriate.
The poll is the latest to find public support for impeachment growing as proceedings against the president gain pace.
However, while Democrats in the house are likely to rule in favour of the president’s removal, it is unlikely the Republican-controlled Senate will endorse the move.
In order for that to happen — a situation that would force Mr Trump from office, making Mike Pence the next commander-in-chief — roughly 20 Republicans would need to abandon Mr Trump, and join a unified Democratic front.
No US president has ever been removed from office by a vote of impeachment.
In 1974 Richard Nixon resigned before a vote could take place, while both Bill Clinton in 1998 and Andrew Johnson in 1868 both retained their positions after they were not removed by the senate.