It didn't take long for an audience member to question the prime minister about the publication of the so-called Russian interference report.

The document in question is an intelligence report into Russian covert actions in the UK by Parliament's Intelligence and Security Committee.

So what exactly is in the Intelligence and Security Committee report?

The BBC's Gordon Corera explains the mystery of the Russia report here.

"I didn't want to have an election now... but we have to do it because Parliament is blocking Brexit," says the PM.

It's put to him that actually Parliament blocked the timetable to pass the PM's deal, not the deal itself.

Mr Johnson tries to argue back against that - to some jeers - and then turns things around to criticism of Jeremy Corbyn.

He says it's not sensible to have more negotiations with Europe as Labour would have.

"I want next year to be a fantastic year... and we need to get Brexit done to do it," he adds.

Iain Watson
Political correspondent

First question to a ruffled haired Boris Johnson is on truth and trust - his standard defence is deployed:

Lack of trust in politics has nothing to do with me, guv - it's Parliament blocking Brexit.

The questioner on trust was actually coming from the perspective of one of the Waspi women - a group deeply upset about pension age changes.

They want those changes reversed and compensation offered.

"I do sympathise deeply with the Waspi women... but it is very expensive to come up with the solution you want," Boris Johnson replies.

"I cannot promise I can magic up that money for you - it is not possible to satisfy all the demands of the Waspi women."

Read more: Waspi campaign - The fight against changes to women's state pension age

As the prime minister takes the floor for the final half hour, here's a quick look at the Conservative Party.

Included is info on Brexit policy, key pledges and the state of the party before Parliament dissolved.

A simple guide to the Tories.

First question - how important is is for someone in your position to always tell the truth?

"I think it is absoolutely vital and I think the issue of trust is central to this election," Boris Johnson replies.

He then moves straight onto Brexit - blaming the failure to deliver it as the main driver of a lack of trust.

This prompts howls from the audience.

The prime minister and Boris Johnson arrives on stage to some cheers and some boos.

After a question about fracking - which Ms Swinson says she is against - the next questioner says crossly that she doesn't believe Jo Swinson is in favour of progressive policies. She says Ms Swinson worked with the Conservatives and spends her time attacking Labour.

In reply, Jo Swinson says it's true, she's not a socialist, she's a liberal. She says sometimes "we do agree with the Labour Party, but we're not the Labour Party".

A switch to a different issue as Jo Swinson is then asked whether she still supports the UK having nuclear weapons.

"We live in a very dangerous world and I think we need to keep our nuclear deterrant, it keeps us safe," the Lib Dem leader replies.

The UK should be leading discussions on how to have a world without nuclear weapons, but until that happens, she argues, we should keep them.

Our political correspondent Iain Watson says:

Just a footnote on nukes - Jo Swinson is criticised for keeing them. It is Labour's official policy to keep the deterrent too, despite Jeremy Corbyn's CND past.

Iain Watson
Political correspondent

It took about half the allotted time slot for Jo Swinson to try to communicate her domestic message - beyond Brexit.

She is very much being defined on how she deals with other parties.

Here is Jo Swinson's difficulty - she has a strong Remain message but clearly, from audience questions there are worries by some Remainers that she will split the anti-Conservative vote, and inadvertently enable Brexit.

"We need to make sure we stop Boris Johnson getting a majority and it's Liberal Democrats who are able to do that," says Jo Swinson on her electoral strategy.

It's not clear Jeremy Corbyn and Labour are able to do that, she adds.

The next questioner is angry at Ms Swinson for bringing up the issue of anit-Semitism - he feels Jeremy Corbyn has fought long and hard against racism.

Ms Swinson says she recognises the questioner really believes that, but says she's going to believe the MPs who've quit Labour because of the abuse they've received.

Reality Check

Jo Swinson claimed that the UK would have more money to spend if it remained in the EU.

It's true that the vast majority of forecasts do expect the economy would be bigger if the UK were to stay in.

The Lib Dems say this would amount to a £50bn "remain bonus" over five years. But this cannot be predicted with any certainty. Also, £50bn is not a hugely significant amount in terms of overall government expenditure.

Jo Swinson is asked how she could bring a country divided by Brexit back together.

"I don't think there's an easy answer to this," she replies.

She acknowledges that people feel "things are too tough, the economy doesn't work for people" but insists "they will be made worse by Brexit".

"We are going to be poorer, it will be worse," the Lib Dem leader argues, but she says remaining would give us more money to spend addressing those issues.

She says other parties are promising things that sound great - like Labour scrapping tuition fees, but there are questions over whether they can be delivered.

On why the Lib Dems aren't promising the same thing, Jo Swinson tells the audience her parties want to prioritise spending on the early years and primary schools.

On possibly joining forces with Jeremy Corbyn, Jo Swinson says she "absolutely" would "work collaboratively" with him, but she has ruled out a coalition.

Why? Well, on Brexit, she says Jeremy Corbyn's position isn't clear - he said he would remain neutral at another referendum tonight.

Ms Swinson also says there's "genuine fear" about the issue of anti-Semitism within Labour, which puts her off joining forces with him.

Image source, PA

An hour into the Question Time leaders' special, Boris Johnson arrived at the venue in Sheffield.

The prime minister is the last of the four leaders to speak, and will take to the stage at around 20:30 GMT.

Image source, Reuters

The Liberal Democrats launched their election manifesto earlier this week, with the slogan Stop Brexit Build A Brighter Future.

The document contains pledges on a variety of subjects, with Brexit and the NHS to the fore.

Here are the policies you should know about.

Iain Watson
Political correspondent

Some senior Lib Dems are worried about being squeezed by the big parties.

Jo Swinson is under huge pressure to prove to Remainers that a vote for her party wouldn't be 'wasted', given that Labour is offering a referendum.

We absolutely got it wrong on tuition fees, says Jo Swinson, but she says she thinks the party has been clearly pro-European, pro-Remain for three years and can be trusted to "stick to our principles".

Do you regret saying you would revoke Article 50 if you won a majority?

"We have to level and be straightforward about it," replies Jo Swinson.

She says the party wants to stop Brexit, so if she got the chance to do that, she would.

During the election campaign period we are profiling the main party leaders.

You can find more on Jo Swinson and the coalition government in the BBC's Jonathan Blake's piece on the Lib Dem leader.

Find the others here:

• Boris Johnson
• Jeremy Corbyn
• Nicola Sturgeon

Two questioners are unhappy that Ms Swinson has said she would revoke Article 50 outright if the Lib Dems won the election - they think it's "undemocratic" given the 2016 result.

"Not for one second does that mean I think people who voted Leave are stupid," Jo Swinson insists. "We disagree."

"You can disagree with me, but you lost!" says the exasperated audience member.

But the Lib Dem leader says even those who back Brexit in Parliament can't agree on how they want it to look.

She says she has led the support for another referendum - "a people's vote" - and will push for that if she doesn't win a majority.

Iain Watson
Political correspondent

Not sure it's a good look to say you called big political events wrong.

Jo Swinson didn't see Trump or Corbyn coming.

(Er don't look at my tweets from that time either...)

Jo Swinson is on the back foot - having to defend her party's record in a Conservative-led government.

With an enhanced profile comes scrutiny, but the audience are being very robust with her.

Perhaps it's not surprising the bold 'Cancel Brexit' position (rather than simply a new referendum) of the Lib Dems is being attacked by some in the audience as "undemocratic".