Labour MPs tore into Jeremy Corbyn’s Brexit strategy at a party meeting on Monday night, with several MPs loyal to the leadership saying they felt ashamed to vote for the party at the European elections and urging a change of direction.

MPs inside the private gathering said there were surprise interventions from colleagues who had never before spoken out against Corbyn, including Lloyd Russell-Moyle and Marie Rimmer.

The parliamentary Labour party (PLP) meeting came amid anger about how Corbyn’s office had handled harassment complaints against two senior Labour figures, as well as an investigation into Labour antisemitism by the equalities watchdog.

One MP leaving the committee room said it had been Corbyn’s “worst meeting in his time as leader” – including those that led to the vote of no confidence in him. “He did not even seem to acknowledge there were difficulties, from Brexit, to sexual harassment, to antisemitism.”

Speaking to MPs for the first time since the European election results, where Labour was beaten into third place by the Liberal Democrats, Corbyn reiterated that the party would back a referendum on any deal passed by parliament and said the issue would be discussed by the shadow cabinet on Tuesday, but the assurances did little to stem the criticism.

Rimmer, whose speech inspired whoops and cheers in the room, told Corbyn: “People who worked with you for years are turning away from us.” In what colleagues described as an emotionally charged speech, Rimmer said that it “wasn’t easy for me to vote Labour” in the EU elections, and “the leadership is not there” on the party’s Brexit policy.

“She eviscerated him,” one Labour MP said. “No one was expecting her to speak out like that.” Another called it “one of the best speeches I have ever heard in here – it clearly came from the heart”.

Russell-Moyle, a key Corbyn loyalist, intervened to insist that MPs should be allowed to criticise senior staff by name if they were influential in policymaking, saying there was “a difference between frontline workers and the management”. His comments were a direct counter to Corbyn, who had earlier called for MPs not to publicly attack staff or the shadow cabinet.

That comment from Corbyn led several MPs to shout, “She’s sitting next to you” and point to shadow foreign secretary Emily Thornberry, who was demoted from her usual slot standing in for Corbyn at PMQs after she criticised the party’s Brexit policy on election night.

In his speech before the interventions, the Labour leader said the party must unite to take on the “dangerously damaging policies” of the Tory leadership candidates, including tax cuts that will benefit the richest, attacks on abortion rights, and a “race-to-the-bottom no-deal Brexit”.

He said Labour was committed to working cross-party to stop no deal. “To break the Brexit deadlock, we need to go back to the people. Let the people decide the country’s future, either in a general election or through a public vote on any deal agreed by parliament,” he said.

One Corbyn ally said they had been taken aback by the tone of the criticism. A Labour source called the meeting “robust”, but said it had not been worse than previous meetings.

“Clearly, there are very strong feelings about Brexit and how it should be handled, both in the Labour party and the country – and among Labour MPs. That’s no secret at all,” the source said.

“We are in a period of heightened polarisation on Brexit, and that is why Jeremy is trying to find a way that reflects our conference policy and that brings the country together. We are listening to the views of members and our MPs … The PLP is very passionate, and that’s what we would expect.”

Corbyn’s comments about ending the criticism of staff were taken to refer to Karie Murphy, his chief of staff, who was criticised in leaked emails for her apparent handling of two harassment complaints, one against senior Labour aide David Prescott and another against Pete Willsman, a member of Labour’s ruling national executive committee who has since been suspended over allegations of antisemitism.

Jess Phillips, the chair of the Women’s PLP, told the meeting the revelations were shameful. “If you abuse women in the Labour party and they’re a friend of yours, they get away with it,” she said, according to MPs in the room. Corbyn robustly denied that was the case, saying she should not have suggested that.

MPs also expressed alarm that Corbyn’s opening speech failed to mention the investigation into antisemitism in the party that has been launched by the Equality and Human Rights Commission.

The party’s handling of antisemitism cases was compared with the automatic expulsion of the former spin doctor Alastair Campbell for admitting he had voted Lib Dem in the European elections. Labour MP Wes Streeting suggested this was a double standard.

Labour’s new Peterborough MP, Lisa Forbes, apologised to MPs at the meeting for liking Facebook posts that referred to “Zionist slavemasters”. But MPs including Margaret Hodge said Forbes had failed to address another aspect of the complaints, her signing of a letter criticising the adoption of the International Holocaust Remembrance Alliance’s definition of antisemitism.

Forbes said she had written to Jewish community groups and hoped to meet the Board of Deputies and the Jewish Labour Movement.