Media playback is unsupported on your device Media caption The Labour leader tells a party activist heckler: "I did all I could"

Jeremy Corbyn has told angry Labour activists he did all he could to prevent the UK leaving the EU.

The Labour leader is facing a no confidence vote over his "lacklustre" campaign for a remain vote.

He vowed to fight off any leadership challenges, and told one activist who heckled him as he attended a Pride march in London: "I did all I could."

Shadow Chancellor John McDonnell said Mr Corbyn "worked himself to the ground" during the four-month campaign.

Mr Corbyn was confronted by Labour Party activist Tom Mauchline at the Pride event, who shouted: "It's your fault, Jeremy. When are you resigning? You need to resign."

During the exchanges, which were filmed and posted on Twitter, Mr Mauchline can be heard saying: "I had a Polish friend in tears because you couldn't get out the vote in Wales, the North and the Midlands."

Mr Mauchline later said he had not known Mr Corbyn would be at the event and became "so angry" when he found out.

"It just seemed like a cynical attempt to use the LGBT community to shore up his weak leadership," he added.

Labour MP Angela Smith told BBC News she and her colleagues are receiving texts and emails from party members "indicating real dissatisfaction with Jeremy's leadership", describing his performance as "nondescript" and "half-hearted".

'Totally amazed'

She added: "Given there's a really strong chance of a general election, and given the importance of taking the country forward to stability, it's really important we've got a really strong leader in place. Jeremy Corbyn we don't believe is that person."

Image copyright Getty Images Image caption Mr McDonnell denied Mr Corbyn was responsible for the EU vote

In a speech on Saturday, Mr Corbyn vowed to ensure Labour's voice was heard on workers' rights, protecting the environment and human rights in the negotiations on Britain's exit from the EU - and he suggested those negotiations should happen soon.

Quizzed afterwards about claims he had run a "half-hearted" campaign for a Remain vote, he said: "Two-thirds of Labour voters voted for Remain in response to our party's call for that."

He added: "There are some people in the Parliamentary Labour Party who would probably want somebody else being the leader of this party, they have made that abundantly clear in the past few days."

Asked if he would stand again if there was a challenge to his leadership, he said: "Yes, I'm here, thank you."

He said he had been "totally amazed" that an online petition had attracted 140,000 signatures from people who do not want Labour spending the next two months debating the party's leadership.

'Did his job'

He also announced a review of immigration policy and ruled out a new EU referendum if Labour wins power.

He said: "The referendum has taken place, a decision has been made, I think we have got to respect that decision and work out our relationship with Europe in the future."

An online petition calling for a second referendum has passed a million signatures.

Image caption Caroline Flint: "I could be a good leader"

Mr McDonnell told BBC News it was wrong to blame Mr Corbyn for the Brexit vote.

"He did his job. He worked himself in to the ground doing meetings after meetings," he said.

"Now trying to blame him or anyone else for what is the democratic decision of our country is wrong. We have just got to say people have made their minds up, they've made a decision, respect it."

He said talk of leadership challenges and confidence motions were a "complete distraction".

"I think people out there in the real world, our constituents, just want us to get on with the job of getting the best deal possible for them," he added.

Two Labour MPs - Dame Margaret Hodge and Ann Coffey - have submitted a motion of no confidence in Mr Corbyn.

Mrs Coffey told BBC News: "The result of the referendum was a disastrous result for us and the leadership must bear a share of the responsibility for that.

"It was a lacklustre campaign, it didn't contain a strong enough message and the leader himself appeared half-hearted about it.

"If you have got a leader who appears half-hearted, you can hardly be surprised if the public feels the same way."

'Decent thing'

The confidence motion has no formal constitutional force but calls for a discussion at the next meeting of the Parliamentary Labour Party (PLP) on Monday.

The PLP chairman, Labour MP John Cryer, will decide whether it is debated. If accepted, a secret ballot of Labour MPs could be held on Tuesday.

The motion's backers Mrs Coffey and Dame Hodge hope it will help build a sense that confidence in Mr Corbyn is draining away, forcing him to quit.

It would take 50 MPs uniting around an alternative candidate to trigger a new leadership contest but none have so far come forward.

Caroline Flint, a former minister on the right of the party, said she would not rule herself out of a leadership bid.

"! think I could be a good leader," she told BBC Radio 5 live.

She said there was "concern across the spectrum" in the party about "whether Jeremy can deliver".

"I think he's a decent guy, a nice guy but we've had lots of decent, nice guys who can't win elections," she added.

Image copyright PA Image caption Frank Field says Mr Corbyn should not lead Labour into next election

Labour MP Frank Field - who supported the Leave campaign - said Mr Corbyn "clearly isn't the right person to lead Labour into an election, because nobody thinks he will win".

"We clearly need somebody who the public think of as an alternative prime minister," he told BBC Radio 4's Today programme.

Former shadow chancellor Chris Leslie, former minister Ben Bradshaw and MP Stephen Kinnock are among those backing the no confidence motion.

An online petition on the website of campaign organisation 38 Degrees calling for "a vote of confidence in Jeremy Corbyn after Brexit" has attracted more than 90,000 signatures from the general public.

However, in a joint statement, union leaders have backed Mr Corbyn to continue as leader, saying the "last thing Labour needs is a manufactured leadership row of its own".

They called for Labour to "unite as a source of national stability" and challenge any attempt to use the referendum result to "introduce a more right-wing Conservative government by the backdoor".