Jackie Speier, who sits on the House Permanent Select Committee on Intelligence, said attempts by the President to pardon members of his family or fire the man appointed to investigate Russian meddling in last year’s presidential election could trigger an impeachment vote.
“I have always thought that he was never going to fulfil his full term,” she said.
“I am more convinced that he will leave before any impeachment would take place.”
On Friday it emerged that the special counsel appointed to investigate Russian meddling in the 2016 vote, Robert Mueller, was using a grand jury – suggesting his probe was entering a new, more serious, phase.
The move piled further pressure on the President, whose seven months in office have been dogged by accusations that his team worked with Russia to swing the vote.
Speaking on Radio 4’s Today programme, Ms Speier said: “I do think the potential for the House to start to think in terms of impeachment is not outside the realm of possibility.
“It is not something that would be happening any time soon but if the President were to act precipitously at any of these situations, pardoning his family members, taking actions to try and get rid of Mr Mueller, I think those would be tipping points and could end up in the House calling for impeachment.”
In order for Mr Trump to be impeached, a simple majority (50 per cent plus one representative) is needed in the House.
A trial would then take place in the Senate, where a two-thirds vote is needed to remove him from office.
Ms Speier said the current makeup of the House of Representatives meant only 24 Republicans were needed to join with Democrats in order to pass an impeachment vote.
Describing the similarities between the Mr Trump and Richard Nixon, who resigned following attempts to impeach him, as “stark”, she said the investigation into the incumbent president “could get very muddy very quickly”, adding: “You can’t make this up, that is what is so mind boggling.”
Mr Mueller was appointed special counsel in May by the justice department following the firing by Mr Trump of FBI director James Comey.
He has since assembled a team of more than a dozen investigators, including current and former justice department prosecutors with experience in international bribery, organised crime and financial fraud.