Hello and welcome to our live coverage of the BBC TV debate between Nick Clegg and Nigel Farage. The Liberal Democrat and UK Independence Party leaders will face each other for an hour on the question of whether the UK should leave or remain in the European Union.
BBC Question Time host David Dimbleby will present and moderate the debate, which is taking place at the BBC's Broadcasting House in central London.
We'll have minute-by-minute updates of the toing and froing between Mr Clegg and Mr Farage, as well as expert analysis from the BBC's political correspondents. We'll also print a selection of reader's views and opinion from across Twitter.
So what's the debate all about? The EU divides opinion throughout the UK - but it is difficult to conceive of a starker divide than the one between Nick Clegg and Nigel Farage.
Nigel Farage rejects the idea that leaving a political union with Europe would harm trade. He also says wages are undercut by EU immigrants. But Nick Clegg claims UKIP is advocating a form of "economic suicide".
Nick Clegg has repeatedly emphasised the importance of EU membership to jobs in the UK, claiming that three million would be at risk if it were to leave - but Nigel Farage says this is "complete and utter nonsense".
On crime, too, the leaders are completely at odds. Nick Clegg says EU co-operation on justice helps bring hundreds of murderers and paedophiles to book, but Nigel Farage complains that it is unnecessary because the UK could reach sensible extradition agreements from outside the EU.
This is round two in the battle between the two leaders. Last week, in a debate hosted by LBC, they clashed on jobs, immigration and the record of Russian President Vladimir Putin. Host David Dimbleby has said one or the other needs to make a few "knockout blows" tonight. In just under an hour we'll find out whether they can.
18:11 FACTCHECKING Anthony Reuben, Head of statistics, BBC News
I'm at Broadcasting House with BBC political analyst Emily Craig. We're going to be checking the facts used in the debate and bringing you instant analysis.