House Speaker Nancy Pelosi appeared to tap the brakes on impeachment discussions, arguing in a letter to her colleagues that while Democrats would hold US President Donald Trump accountable, they could do so without initiating impeachment hearings.

The California Democrat, who is slated to address her caucus on a conference call today, vowed that Democratic investigators "will scrupulously assert Congress's constitutional duty to honour our oath of office to support and defend the Constitution and our democracy" by investigating the President.

"Whether currently indictable or not, it is clear that the President has, at a minimum, engaged in highly unethical and unscrupulous behaviour which does not bring honour to the office he holds," Pelosi wrote.

But the Speaker offered a word of caution on impeachment - a step pushed by some 2020 presidential hopefuls, most notably Senator Elizabeth Warren, in the days following the Mueller report's release.


Without ruling out the concept altogether, Pelosi noted that "it is . . . important to know that the facts regarding holding the President accountable can be gained outside of impeachment hearings."

Trying to strike a note of unity, Pelosi added: "While our views range from proceeding to investigate the findings of the Mueller report or proceeding directly to impeachment, we all firmly agree that we should proceed down a path of finding the truth".

She added: "As we proceed to uncover the truth and present additional needed reforms to protect our democracy, we must show the American people we are proceeding free from passion or prejudice, strictly on the presentation of fact."

Pelosi's comments come as several of her Democratic chairmen suggested on talk shows that impeachment might be an option. Pelosi, before the Mueller report, has argued that impeachment was too divisive, politically costly and that Trump was "not worth it".

Pelosi also set a high threshold for taking up impeachment, arguing that it would have to be bipartisan. But Republicans following the Mueller report's release have largely gone silent, even as Mueller detailed the Trump campaign welcoming Russia's interference in the 2016 election and Trump's effort to thwart the investigation.

Mueller, however, did not establish conspiracy and did not answer the question of whether Trump obstructed justice, appearing to kick the issue to Congress. Attorney-General William Barr said the President did not obstruct justice.

Pelosi in her letter took a shot at the Republican Party for its muted reaction to the Special Counsel's report.

"It is also clear that the congressional Republicans have an unlimited appetite for such low standards," she wrote. "The GOP should be ashamed of what the Mueller report has revealed, instead of giving the President their blessings."


Pelosi also called on the GOP-controlled Senate to take up campaign finance legislation that passed the House earlier this year, which included sweeping ethics reforms. Yesterday, the President's legal team argued that it was acceptable for the Trump campaign to seek to benefit from Russia's hacking of the Clinton campaign.

"[I]n light of the President's defenders arguing in defence of receiving and weaponising stolen emails, we continue to press our Republican House counterparts to take up our pledge to refuse to use stolen, hacked, or falsified information in campaigns because the American people deserve honest debate," Pelosi wrote.

White House officials taunted House Democrats as they considered their next steps.

"If they have to get a conference call together to figure out where they're going from here, they shouldn't be in office in the first place," said White House press secretary Sarah Sanders on Fox News.

"I think it's quite sad that they've got to have a conference call with all of their members to figure out what they're going to do with themselves now that the Mueller report is out and proven that there was no collusion and no obstruction."