Nick Eardley
Political correspondent

The first question is an early reminder that these two leaders have caused division in their own parties.

It is quite something that former Labour and Tory PMs don’t want their successors to win a majority at this election.

Jennifer Scott
BBC News

And it's suddenly gone quiet in the spin room, after the live feed went down.

The first question is from John Purcell. He asks: "Is Sir John Major’s recent intervention worrying to you, Mr Johnson? And Mr Blair's intervention worrying to you, Mr Corbyn?"

Mr Johnson says he has the "utmost respect" for former PMs but he "doesn't think it's right".

He says his government could "get Brexit done". He says his party is now "totally united".

"The mystery is what is the position of the opposition leader," he says.

Mr Corbyn says what's key is the future of this country.

He says there is a risk of a trade deal with Donald Trump which will threaten our public services.

He says the former PMs are allowed to have their own opinions.

Nick Eardley
Political correspondent

Boris Johnson’s opening statement was - unsurprisingly - very on message, too.

It only took a few seconds to hear that big election pitch of his: “Get Brexit done.”

Now Boris Johnson's opening statement.

"On Thursday next week this country reaches a turning point," says the PM.

"The only way to unleash the potential of this whole country is if we get a working majority."

He says the alternative - Labour - would mean further referendums on EU membership and Scottish independence.

"Let's get Brexit done with a one nation Conservative government and take this country forward," he concludes.

Nick Eardley
Political correspondent

Jeremy Corbyn’s pitch at the start stuck to his key themes in this election - his plans to invest in public services and asking the rich to pay more for it.

Jeremy Corbyn has begun the debate with his opening statement - he won a coin toss and decided to go first earlier.

He says: "Labour is ambitious for our country and ambitious for you."

He wants “real opportunity for all”.

There are four million children living in poverty in the UK and millions of families are struggling to make ends meet, he says.

"A vote for Labour is a vote for hope a vote for real change," he adds.

Jennifer Scott
BBC News

The live one-hour debate between Boris Johnson and Jeremy Corbyn has begun.

Remember - this is the last time the Conservative Party and Labour leaders will share a stage before polling day on 12 December.

Their policies on Brexit, the NHS and the economy are likely to come under scrutiny, as are issues of trust and character.

We'll have all the latest here.

Jennifer Scott
BBC News

Five minutes to go and there is a bit more hush in the spin room.

The cameras are down, the screens are up and people are waiting to see what the leaders have to offer.

I have just seen Nick Robinson striding to the studio and wished him luck.

He called out "thank you", but that was a man on a mission, waiting to host one of the biggest moments of this election campaign.

Who will come out on top? In just over an hour, when the debate is wrapped up, things will be clearer.

BBC Radio 5 Live

Sir John Curtice, professor of politics at Strathclyde University, says the opinion polls might well suggest that people think Boris Johnson should do an interview with Andrew Neil.

"But I am tempted to say it is an issue that is of great excitement to journalists but I am not sure it is an issue that will be crucial to the election," he tells BBC Radio 5 Live.

"He has been picky for a while about what interviews to do, and to that extent we are not learning anything new about the prime minister."

It certainly doesn't affect his central message of "get Brexit done”, Prof Curtice adds.

John Pienaar
Pienaar’s Politics

There's nothing like a bit of close proximity to crank things up by a few megawatts.

I don't think there's any great personal animus between the two men, but I think there's pretty close to zero respect, and they view each other - I would say - with a kind of detached, distant detestation.

For Jeremy Corbyn, Boris Johnson is an over-privileged, Oxbridge-educated toff from a reasonably well-off background with every privilege in life - in his career and his political life too - and he has no time for that at all.

For Boris Johnson, Jeremy Corbyn is the epitome of an old-school left-winger. When he accuses Mr Corbyn of being someone who dislikes Britain, doesn't like the West, dislikes success and enterprise, he absolutely means it.

With the latest televised election special just 10 minutes away, what have we seen from the politicians to date...

• 19 Nov - ITV debate sees Boris Johnson and Jeremy Corbyn clash over NHS and Brexit
• 22 Nov - Labour's Jeremy Corbyn, Conservative Boris Johnson, the SNP's Nicola Sturgeon and the Lib Dems' Jo Swinson face members of the public in a Question Time leaders' special from Sheffield
• 28 Nov - Five party leaders take part in Channel 4's climate debate. Boris Johnson and Nigel Farage choose not to take part and are replaced by melting ice sculptures
• 29 Nov - Figures from seven political parties square off for the first time on television in this election campaign, debating Brexit, the economy, immigration and the NHS
• 1 Dec - Second ITV debate sees leading figures from the UK's political parties clash on Brexit, the NHS and terror legislation

Jennifer Scott
BBC News

We heard from my colleague Nick Eardley a little while ago on the tactics coming from Team Corbyn - and how they're likely to be pretty familiar.

Well, after a chat with Team Johnson, we can safely say we're not expecting a change in tune from the PM either.

Tonight's plan is to double down on the messages he has already been putting out there - get Brexit done, money for the NHS and investment in schools.

But with that first jab comes the follow up - to make clear to the public the choice they have on Thursday, and what the Tories believe is the risk, between Mr Johnson and the "chief ditherer" Jeremy Corbyn.

This doesn't mean the Tories are setting themselves up for a fall, though. They know there is still time for the polls to change and they know they don't have No 10 in the bag yet.

But they are sticking to their strategy and hoping it pays off.

We've seen a few of Jeremy Corbyn's top team at the debate venue and now here's one of his opponent's.

Foreign Secretary Dominic Raab has arrived - no doubt to take part in the "spinning" afterwards, when each side does their best to insist that their man won.

Image source, PA Media

The prime minister is in the building...

Boris Johnson shook hands with BBC director of news Fran Unsworth after stepping out of the car.

Nick Eardley
Political correspondent

Tonight’s debate is one of the last big chances for the two men who could be prime minister this time next week to win you over; to try and seize the narrative, or blow a hole in their opponent’s argument.

Let’s face it - the main campaign messages have been trotted out at every opportunity over the last few weeks and we know what they are.

Expect more of that tonight. Boris Johnson will tell you he can "get Brexit done" (others say that’s over promising). Jeremy Corbyn will tell you the NHS is vulnerable if he loses (others say that’s nonsense).

But the most important part of tonight will be the scrutiny. How do our prospective PMs fair under sustained questioning from their rival and the pressure of a big audience at home?

Mr Johnson probably has more to lose. Polls suggest his party maintains a fairly comfortable lead over Labour - and I think the Tory leader will continue to try and play it safe tonight. To not slip up, rather than do something new or spectacular.

Mr Corbyn, arguably, has more to do. Can he do something which starts to move the polls and close the gap? Can he create some doubt about Mr Johnson’s plans and persuade you that his are more deliverable?

This time next week we’ll know most if not all of the election results. One of the men appearing tonight will be on course to be prime minister - the other may well be facing calls to quit. Tonight's debate could well play an important role in deciding which is which.

Brexit: The two leaders clashed on this key issue in their previous debate and they inevitably will again. Expect to hear "get Brexit done" from Boris Johnson. From Jeremy Corbyn, it's an offer to "get Brexit sorted" by renegotiating Mr Johnson's deal with the EU and then putting that to a public vote.You can find out more about where the parties stand on Brext here.

The NHS: Both parties agree the National Health Service needs more money but they have clashed over whether it will be part of any post-Brexit trade negotiations with the US. Labour says the NHS is at risk because of the Conservatives' plans. The Tories say these claims are "nonsense". You can read more about promises on the NHS here.

Security: The debate takes place just a week after the London Bridge attack, in which two people were killed. Questions on this incident, the response of the leaders, UK security and tougher sentences for violent offenders are likely.

Racism: Both the Conservatives and Labour have had internal rows over claims of racism - the Tories over allegations of Islamophobia and Labour amid claims of anti-Semitism.

Climate change: There have been a number of "green" pledges in this election so far. The Conservative government has committed to cutting emissions to zero by 2050. Labour wants to reduce emissions "substantially" by 2030.