WASHINGTON, United States (AFP) — US House Speaker Nancy Pelosi told congressional leaders Thursday to draft articles of impeachment against Donald Trump, saying the president’s abuse of power “leaves us no choice but to act.”

By asking the House Judiciary Committee chairman to draw up the charges, Pelosi, the top congressional Democrat, signalled that a formal impeachment process against the 45th president is all but assured.

With a majority of members in the Democratic-controlled chamber already expressing intent to back the deeply divisive procedure, Trump is likely to become just the third president in US history to be impeached by the House of Representatives.

“Sadly, but with confidence and humility, with allegiance to our founders and a heart full of love for America, today I am asking our chairman to proceed with articles of impeachment,” Pelosi said in a short, sombre televised statement.

Trump “has engaged in abuse of power, undermined our national security and jeopardised the integrity of our elections,” she said, adding that “the president leaves us no choice but to act.”

Pelosi did not announce the charges, but Trump could face impeachment for abuse of power, obstruction of Congress and obstruction of justice.

– Trump ‘abused his power’ –

She said that “the president abused his power for his own political benefit” by withholding military aid to Ukraine and a White House meeting in exchange for Kiev’s commitment to investigate Trump’s political rival Joe Biden.

“If we allow a president to be above the law, we do so surely at the peril of our republic,” added the speaker, Trump’s chief nemesis in Congress.

Trump’s spokeswoman Stephanie Grisham shot back, saying Democrats should be “ashamed” for pulling the trigger on impeachment.

Trump goaded his Democrat opponents, saying that if they wanted to impeach him they should press ahead now so that he can have a “fair trial” in the Senate, where his Republican Party holds power.

The defiant president continued his online rant, saying Democrats were seeking to impeach him “over NOTHING.”

“The good thing is that the Republicans have NEVER been more united,” Trump tweeted. “We will win!”

The impeachment process is expected to proceed rapidly, with articles likely presented for a full House vote later this month after weeks of hearings.

“If you are going to impeach me, do it now, fast, so we can have a fair trial in the Senate, and so that our country can get back to business,” Trump tweeted.

Trump’s re-election campaign weighed in too, saying the Democrats have long pushed impeachment as a way to negate the results of the 2016 election.

“They should just get on with it,” Trump campaign manager Brad Parscale said in a statement.

Democrats want a timely process too, as they do not want an impeachment to drag into their party’s voting process that decides the 2020 presidential nominee.

Democrats have been building a case that Trump should be impeached for trying to leverage a White House meeting and military aid to pressure Ukraine for dirt on Biden, Trump’s potential rival in the 2020 election.

On Wednesday, three constitutional scholars told the House Judiciary Committee that the president’s actions seeking foreign interference in US elections were clear grounds for removal.

A Democrat on the panel, Steve Cohen, said the articles of impeachment will “certainly” include abuse of power and the obstruction of Congress.

“It’s possible we’ll get to obstruction of justice,” Cohen told CNN.

Republicans in Congress appeared to present a united front against the process.

“Dems have no case,” number two House Republican Steve Scalise tweeted. “She’s rushing because she knows she’s lost public support.”

Polling shows Americans are about evenly split on impeaching and removing Trump.

According to a FiveThirtyEight.com poll average, 46.8 per cent of respondents support impeachment and removal, versus 44.5 per cent who do not.