Jeremy Corbyn has declared he will be “neutral” in a second Brexit referendum, in a stormy general election Question Time which saw Boris Johnson forced to defend himself against charges of racism.

The Labour leader has come under intense pressure to say whether he would back Leave or Remain in the Final Say vote which he has promised within six months if Labour wins the 12 December general election.

Labour says it will decide its position at a special conference in the spring, but Mr Corbyn's announcement that he will not personally take sides will heighten expectations that MPs will be allowed to campaign either for or against the “credible” Brexit deal which their leader says he will negotiate with Brussels.

Asked which side he would campaign on, Mr Corbyn said: “I will adopt, as prime minister at the time, a neutral stance, so I can credibly carry out the result of that to bring our communities and country together.”

Adopting a neutral stance would bring to a stop the “endless debate about the EU and Brexit”, he said.

But he was jeered by sections of the audience as he insisted he would be able to negotiate a credible Brexit deal.

General election: Facts and figures Show all 79 1 /79 General election: Facts and figures General election: Facts and figures General election 2019 opinion polls General Election 2019 opinion polls. See story POLITICS Election. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Estimated declaration time General Election 2019 estimated declaration times. See story POLITICS Election. Infographic by PA Graphics PA Graphics Press Association Images General election: Facts and figures 'Big beasts' at risk General Election 2019 'big beasts' at risk. See story POLITICS Election. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Smallest majorities at 2017 general election Smallest majorities at 2017 general election. See story POLITICS Election. Infographic by PA Graphics PA Graphics Press Association Images General election: Facts and figures Turnout at UK general elections Turnout at UK general elections. See story POLITICS Election. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures General election 2019 poll of polls General Election 2019 poll of polls. See story POLITICS Election. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Vote shares at general elections since 1945 Vote shares at general elections since 1945. See story POLITICS Election. Infographic by PA Graphics PA Graphics Press Association Images General election: Facts and figures Seats to watch in North-west England General election 2019 seats to watch in North-west England. See story POLITICS Election NorthWest. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Women MPs at UK general elections Women MPs at UK general elections. See story POLITICS Election. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures General election 2019 leaders' visits - Boris Johnson and Jeremy Corbyn General Election 2019 leaders' visits. See story POLITICS Election Visits. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Boris Johnson's campaign visits so far General Election 2019: Boris Johnson's campaign visits so far. Infographic from PA Graphics. Charlotte Hodges Press Association Images General election: Facts and figures Jeremy Corbyn's campaign visits so far General Election 2019: Jeremy Corbyn's campaign visits so far. Infographic from PA Graphics. Charlotte Hodges Press Association Images General election: Facts and figures Pound v dollar Pound v dollar. See story POLITICS Election. Infographic by PA Graphics PA Graphics Press Association Images General election: Facts and figures General election 2019 opinion polls in Wales General Election 2019 opinion polls in Wales. See story POLITICS Election. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Seats to watch in London General election 2019 seats to watch in London See story POLITICS Election London. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Seats to watch in Wales General Election 2019 seats to watch in Wales. See story POLITICS Election WalesSeats. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Seats to watch in Eastern England General election 2019 seats to watch in Eastern England. See story POLITICS Election Eastern. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures General election 2019 leaders' visits so far General Election 2019: leaders' visits so far. Infographic from PA Graphics. Charlotte Hodges Press Association Images General election: Facts and figures Seats to watch in south-east England General Election 2019 seats to watch, south-east England. See story POLITICS Election SouthEast. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures General election 2019 leaders' visits General Election 2019 leaders' visits. See story POLITICS Election Visits. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Historic Labour seats at risk General Election 2019: historic Labour seats at risk. See story POLITICS Election Historic. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Opinion polls (one week to go) v election result 2017 Opinion polls v election rsult 2017. See story POLITICS Election Polls. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures General election 2019 polls in Scotland General Election 2019 opinion polls in Scotland. See story POLITICS Election Poll Scotland. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Opinion polls (one week to go) v election result 2015 Opinion polls v election result 2015. See story POLITICS Election Polls. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Seats to watch in West Midlands General election 2019 seats to watch in the West Midlands. See story POLITICS Election WestMidlands. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Bellwether seats Bellwether seats at UK general elections. See story POLITICS Election Bellwethers. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Conservative top targets General Election 2019 Conservative top targets. See story POLITICS Election Conservatives. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures General election 2019 polls in London General Election 2019 opinion polls in London. See story POLITICS Election. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Leaders' approval ratings, July-December Leaders' approval ratings. See story POLITICS Election. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Seats to watch in Yorkshire General election 2019 seats to watch in Yorkshire. See story POLITICS Election Yorkshire. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures General election 2019 timetable General Election 2019 timetable. See story POLITICS Election. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Labour top targets General Election 2019 Labour top targets. Infographic PA graphics PA Graphics Press Association Images General election: Facts and figures Seats to watch in north-east England General Election 2019 seats to watch, north-east England. See story POLITICS Election NorthEast. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures When parliamentary seats last changed hands When parliamentary seats last changed hands. See story POLITICS Election Seats. Infographic by PA Graphics PA Graphics Press Association Images General election: Facts and figures Seats to watch in the East Midlands General election 2019 seats to watch in the East Midlands. See story POLITICS Election EastMidlands. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Seats to watch in south-west England General election 2019 seats to watch in south-west England. See story POLITICS Election SouthWest. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Planned increase in day-to-day departmental spending General Election 2019 planned increase in day-to-day departmental spending. See story POLITICS Election IFS. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Corporation tax rates General Election 2019 corporation tax rates. See story POLITICS Election IFS. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Opinion polls (two weeks to go) v election result 2017 Opinion polls v election result 2017. See story POLITICS Election Polls. Infographic by PA Graphics. PA Graphics Press Association Images General election: Facts and figures Opinion polls (two weeks to go) v election result 2015 Opinion polls v election result 2015. See story POLITICS Election Polls. Infographic by PA Graphics. PA Graphics Press Association Images General election: Facts and figures Hospital admissions in England for poisoning by drug misuse. See story POLITICS Drugs. Infographic by PA Graphics PA Graphics Press Association Images General election: Facts and figures Applications to register to vote Applications to register to vote. See story POLITICS Election Voting. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures How many women MPs could there be after the election? How many women MPs could there be after the election? See story POLITICS Election Women. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures General election 2019 opinion polls in Wales General Election 2019 opinion polls in Wales. See story POLITICS Election. Infographic by PA Graphics PA Graphics Press Association Images General election: Facts and figures A comparison of the length of the manifestos of the main parties A comparison of the length of the manifestos of the main parties. Infographic from PA Graphics. Charlotte Hodges Press Association Images General election: Facts and figures Mentions of key words in the main party manifestos Mentions of key words in the main party manifestos. Infographic from PA Graphics. Charlotte Hodges Press Association Images General election: Facts and figures Mentions of key words in the main party manifestos Mentions of key words in the main party manifestos. Infographic from PA Graphics. Charlotte Hodges Press Association Images General election: Facts and figures Leaders' approval ratings, July-November Leaders' approval ratings. See story POLITICS Election. Infographic by PA Graphics PA Graphics Press Association Images General election: Facts and figures Council houses built in the UK 1951-2018 Council houses built in the UK 1951-2018. See story POLITICS Election Labour Housing. Infographic from PA graphics PA Graphics Press Association Images General election: Facts and figures Council houses built in the UK Council houses built in the UK. See story POLITICS Election Labour Housing. Infographic from PA graphics Press Association Images General election: Facts and figures Opinion polls (three weeks to go) v election result 2015 Opinion polls v election result 2015. See story POLITICS Election Polls. Infographic by PA Graphics. PA Graphics Press Association Images General election: Facts and figures Opinion polls (three weeks to go) v election result 2017 Opinion polls v election result 2017. See story POLITICS Election Polls. Infographic by PA Graphics. PA Graphics Press Association Images General election: Facts and figures General election 2019 target seats General election 2019 target seats. See story POLITICS Election. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Lib Dem targets General Election 2019 Lib Dem targets. Infographic by PA Graphics PA Graphics Press Association Images General election: Facts and figures SNP targets General Election 2019 SNP targets. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Plaid Cymru targets General Election 2019 Plaid Cymru targets. See story POLITICS Election Plaid. Infographic by PA Graphics PA Graphics Press Association Images General election: Facts and figures Prime ministers with shortest time in office Prime ministers with shortest time in office. See story POLITICS Election PrimeMinister. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Applications to register to vote Applications to register to vote. See story POLITICS Election Voting. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Major toll roads & bridges in Great Britain Major toll roads & bridges in Great Britain. See story POLITICS Election Labour Tolls. Infographic from PA graphics PA Graphics Press Association Images General election: Facts and figures Police workforce in England and Wales Police workforce in England and Wales. See story POLITICS Election Tories Knife. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Police officers in England and Wales Police officers in England and Wales. Infographic from PA Graphics. Charlotte Hodges Press Association Images General election: Facts and figures Police-recorded homicides in England and Wales Police-recorded homicides in England and Wales. See story POLITICS Election Tories Knife. Infographic by PA Graphics PA Graphics Press Association Images General election: Facts and figures Knife crime offences recorded by police in England and Wales Knife crime offences recorded by police in England and Wales. See story POLITICS Election Tories Knife. Infographic by PA Graphics PA Graphics Press Association Images General election: Facts and figures Opinion polls in 2019 Opinion polls in 2019. See story POLITICS Election. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Number of candidates per seat Number of candidates per seat at the 2019 General Election. Infographic from PA Graphics. Charlotte Hodges Press Association Images General election: Facts and figures Candidates standing in the 2019 General Election Candidates standing in the 2019 General Election. Infographic from PA Graphics. Charlotte Hodges Press Association Images General election: Facts and figures Candidates at UK general elections since 1979 Candidates at UK general elections since 1979. Infographic from PA Graphics. Charlotte Hodges Press Association Images General election: Facts and figures Women candidates at the 2019 General Election Women candidates at the 2019 General Election. Infographic from PA Graphics. Charlotte Hodges Press Association Images General election: Facts and figures Prime ministers with smallest constituency majorities to defend Prime ministers with smallest constituency majorities to defend at a general election. See story POLITICS Election Majority. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Cost of administering polls since 2010 Cost of administering polls since 2010. See story POLITICS Election Cost. Infographic by PA Graphics. Embargoed to 0001 Wednesday November 6 PA Graphics Press Association Images General election: Facts and figures People's Vote group priority list of recommended candidates in key target seats People's Vote group revealed its priority list of recommended candidates in key target seats. See story POLITICS Election Vote. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures MPs retiring from the House of Commons at general elections MPs retiring from the House of Commons at general elections. See story POLITICS Elections. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Lib Dems/Plaid Cymru/Green pact in Wales Lib Dems/Plaid Cymru/Green pact in Wales. See POLITICS Election Pact Seats. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Lib Dems/Green pact in England, seats where Greens have stood down in favour of Lib Dems Lib Dems/Green pact in England, seats where Greens have stood down in favour of Lib Dems. See story POLITICS Election Pact Seats. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Lib Dems/Green pact in England Lib Dems/Green pact in England. See story POLITICS Election Pact Seats. Infographic by PA Graphics PA Graphics Press Association Images General election: Facts and figures Nationality of NHS workforce in England Nationality of NHS workforce in England. See story POLITICS Election. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Proportion of NHS workforce in England who are not UK nationals Proportion of NHS workforce in England who are not UK nationals. See story POLITICS Election. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Long-term net migration to the UK Long-term net migration to the UK. See story POLITICS Election Immigration. Infographic PA Graphics PA Graphics Press Association Images General election: Facts and figures Shortest parliamentary sessions since First World War Shortest parliamentary sessions since First World War. See story POLITICS Election Dissolution. Infographic PA Graphics PA Graphics Press Association Images

Mr Johnson said that Corbyn’s position “seems to have mutated”.

“He now says he’s going to be neutral on the deal that he proposes to do,” said the prime minister. “I don’t see how he can do a deal when he wants to be neutral.”

Mr Johnson returned repeatedly during his 30-minute grilling to his well-worn argument that Britain must “get Brexit done” in order to move on. But he faced boos as he claimed that the failure to deliver Brexit was to blame for a loss of trust in politics.

And there was laughter from the studio audience when the prime minister said it was “absolutely vital” to tell the truth in the election.

Mr Johnson faced hostile questioning over past newspaper columns which have been denounced as Islamophobic and homophobic and was forced to deny being personally responsible for the growth of “racist rhetoric” in society.

Defending notorious comments about “tank-topped bum boys” and Muslim women looking like “letterboxes”, the prime minister said: “I defend my right to speak out.”

Boris Johnson challenged by Fiona Bruce over comments written in columns

Mr Johnson has been dogged by the articles he wrote as a journalist, including the recent revelation that he wrote that seeing “a bunch of black kids” scared him.

He denied the phrases were offensive – claiming they could only be “made to seem offensive” if taken out of context.

“If you go through all my articles with a fine-toothed comb and pick out individual phrases, there’s no doubt that you can take out things that can be made to seem offensive,” he told the BBC Question Time audience.

Mr Corbyn faced tough questioning during the two-hour broadcast over his own record on handling antisemitism in his party.

One audience member said he was “terrified” to see footage of Corbyn shake the hand of an activist who had heckled Jewish MP Ruth Smeeth out of a meeting, and told him “I don’t buy this whole ‘nice old grandpa’. I see that video and that tells me all I need to know.”

Mr Corbyn accepted that Ms Smeeth and others had suffered “unbelieveable” levels of abuse, but added: “Bad behaviour, misogyny, racism in any form is absolutely not acceptable in any form whatsoever in my party or in society.”

Mr Johnson was loudly barracked as he defended his decision – which he said he had taken “ages ago” – not to have a parliamentary report on alleged Russian interference in UK politics published before the election.

He appeared to suggest critics of the decision, such as the Intelligence and Security Committee chairman Dominic Grieve, were conspiracy theorists, as he said: “This is complete Bermuda Triangle stuff”.

Reports suggest that the investigation looked into alleged links between wealthy Russian nationals and the Conservative party and claims of interference in the 2016 EU referendum.

Mr Johnson said: “There is absolutely no evidence at all to show any influence into any British electoral event.

“And the reason I won’t (publish) – or at least the reason I decided not to ages ago – is that I see no reason to interfere with the normal timetable just because there is an election going on.”

Also given a rough ride by questioners on the special general election broadcast was Liberal Democrat leader Jo Swinson, who apologised for her role in supporting the increase in university tuition fees in the coalition government and admitted her party “didn’t get everything right” on austerity while in government.

After entering the election on a pitch that she could become prime minister, Ms Swinson acknowledged that it would be “a strange thing” if she ended up in Downing Street.

Jo Swinson (EPA)

She made clear the Lib Dems were now presenting themselves not as a potential government but as the best means for preventing a majority Tory administration.

Declaring herself “dismayed” at the choice between Johnson and Corbyn for prime minister, she said: “It’s the Liberal Democrats who are able to win seats from Boris Johnson and the Tories. It’s not the case that Jeremy Corbyn and he Labour Party are going to be able to win seats from the Conservatives..

“That’s why voting Liberal Democrat is the way to deprive Boris Johnson of a majority.”

Rejecting suggestions that she was splitting the pro-referendum vote by standing against Labour, she said “my conscience wouldn’t be clear” if she did not ensure the electorate had a chance to vote to stop Brexit, warning: “This might be the last chance.”

Asked if she would form another Lib Den-Tory coalition, Ms Swinson said “certainly not under Boris Johnson”, describing the Tories as “off the charts” under his leadership.

Mr Corbyn again rejected the prime minister’s charge that he would usher in a second independence referendum in Scotland, saying he would not allow it for “two years at least” after taking power.

But Scottish first minister Nicolas Sturgeon said she believed that Mr Corbyn would drop his resistance to an “IndyRef2” if he needed SNP support for a minority administration in a hung parliament.

“Having heard Jeremy Corbyn, do you think he is going to walk away from the chance to end austerity, to protect the NHS, to stop Universal Credit, simply because he wants for a couple of years to prevent Scotland having the right to self-determination?” she asked.