Two former Canadian cabinet ministers have been expelled from their party after Justin Trudeau said they could no longer be trusted, as a bitter political scandal continues to inflict political damage on the ruling Liberal party.

Jody Wilson-Raybould, the country’s former justice minister and attorney general, and Jane Philpott, the former president of the treasury board, were expelled on Tuesday, following a vote by members.

“The trust that previously existed between these two individuals and our team has been broken,” said Trudeau after the meeting.

The extraordinary move is unlikely to put an end to the scandal, which broke out over allegations of bribery in Libya, but is now posing a serious threat to the Liberal party’s chances in this fall’s general election.

I have just been informed by the Prime Minister of Canada that I am removed from the Liberal caucus and as the confirmed Vancouver Granville candidate for the Liberal Party of Canada in the 2019 federal election. More to come... — Jody Wilson-Raybould (@Puglaas) April 2, 2019

Wilson-Raybould and Philpott were both widely seen as rising stars in the party, and their sudden exit has cast a shadow over Trudeau’s domestic image as a leader committed to transparent government.

Both women resigned from the cabinet earlier in the year, over allegations that the prime minister and his aides had improperly pressured Wilson-Raybould to abandon the prosecution of engineering giant SNC Lavalin, which is fighting charges of bribery and corruption while pursuing lucrative construction contracts in Libya.

Nevertheless, the two women remained in the Liberal party, and before Tuesday’s meeting, Wilson-Raybould wrote in a letter to party members that she still believed in Liberal values.

“I am angry, hurt, and frustrated because I feel and believe I was upholding the values that we all committed to,” she wrote. “Ultimately the choice that is before you is about what kind of party you want to be a part of, what values it will uphold, the vision that animates it, and indeed the type of people it will attract and make it up.”

But the Liberal MP Judy Sgro – who voted to remove Wilson-Raybould – called the letter “too little, too late”.

In previous weeks, the prime minister had rejected the idea of expelling the two rookie members, citing the importance of spirited debate within the party.

But the mood in the party cooled last week, after it was revealed Wilson-Raybould had secretly taped a conversation with the then clerk of the privy council, Michael Wernick, as the two discussed the SNC Lavalin case.

In the recording – which was submitted as evidence to the parliamentary justice committee – she expresses concern the prime minister was breaching constitutional norms and says her refusal to override prosecutors is out of a desire to protect the prime minister.

While it is not illegal to record a conversation in Canada if the person recording is part of conversation, the Canadian Bar Association frowns on the practice – something Wilson-Raybould acknowledged when she called the recording an “extraordinary and otherwise inappropriate step”.

Her explanations, however, did little to placate fellow parliamentarians.

“When the top lawyer in the country and the clerk of the privy council are having a conversation about something very important, it is totally inappropriate to record without notifying the other person,” the transport minister, Marc Garneau, told reporters. “It is not an honourable thing to do.”

Philpott has also created controversy inside the party with an interview in Maclean’s magazine, in which she criticized the “attempt to politically interfere with the justice system in its work on the criminal trial”.

Earlier on Tuesday, Philpott also expressed continuing loyalty to Trudeau, but after the meeting she described the vote as “profoundly disheartening”.

“I did not initiate the crisis now facing the party or the prime minister. Nor did Jody Wilson-Raybould,” said Philpott in a statement.

The affair has further called into question Trudeau’s commitment to reconciliation with indigenous peoples in Canada: Wilson-Raybould was the first indigenous person to hold the position of attorney general, and her removal from the party is likely to have deep reverberations in communities across across the country.

While Trudeau has retained support within his party, the scandal continues to be politically damaging for the Liberals: recently polling shows the party trailing the Conservatives by up to six percentage points.

In a statement on Tuesday evening, the Conservative leader, Andrew Scheer, said the Liberals had “chosen to condemn colleagues who spoke truth to power and to prop up a prime minister who is drowning in scandal”.