Joe Twyman, head of political research at the polling firm YouGov, concludes that the debate is a "score draw" and the parties are "heading for penalties".

In Glasgow, the Scottish First Minister is challenged on the SNP’s previous line that last year’s Scottish independence referendum was a once-in-a-generation vote.

“If you (the people of Scotland) want it to be once in 20 lifetimes, that’s what will happen. I can’t impose a referendum on Scotland against its will.”

After the programme, Conservative Chancellor George Osborne has high praise for his party leader. "David Cameron is out there," he says, "turbo-charged on the election campaign trail".

A Guardian/ICM poll has David Cameron as the winner on 44%, with Ed Miliband on 38%. Sky political editor Faisal Islam reckons Mr Cameron gave his best performance of these debates. He notes that Mr Miliband got his message out with a "cast iron" ruling out of a Labour/SNP coalition.

UKIP's Paul Nuttall is in the Leeds spin room talking to Adam Boulton from Sky News. He doesn't think any of the party leaders who've appeared in broadcasts so far will see any "bounce in the polls" as a result of the debate. He reckons we saw the "same old tired politicians".

“I have never ruled anything out," says Ms Sturgeon. "But I have also said, and before Ed Miliband by the way, the most likely outcome is where we are supporting a Labour minority government on an issue-by-issue basis.”

In Glasgow, Ms Sturgeon tells her audience: “I am proposing real term spending increases over the lifetime of this Parliament."

The post-match analysis gets under way with William Hague seizing on Ed Miliband's remark that he didn't think the Labour government had overspent. Mr Hague exclaims:

Reality Check

We'll keep on picking over some of those claims made by the party leaders. Nick Clegg says that roughly the same number of citizens of other EU states are living and working in the UK as there are UK citizens living and working elsewhere in the EU.

The answer to this parliamentary question, external puts the number of UK citizens living elsewhere in the EU in 2010 at 2.2 million. From the 2011 Census we know that there were 2.3 million people in the UK with "other EU" passports.

Brian Shepherd:

The problem with this election is that anyone of the party leaders could lead each other's parties as they all sound the same.

Back in Leeds, journalists and politicians tumble into the spin room. Chancellor George Osborne is there as well as former Lib Dem leader Paddy Ashdown.

Ms Sturgeon is asked: "Who do you think would be more effective in the next Westminster parliament - a Scottish Labour cabinet minister or an SNP backbencher?"

She says the SNP would have “big influence and big clout”.

Scottish National Party leader Nicola Sturgeon is about to take her first question from the audience at BBC Scotland’s Glasgow HQ as part of tonight’s leaders’ debate.

Nick Clegg's session comes to a close with a question from David Dimbleby. Would Mr Clegg stay on as leader if his party couldn't form a coalition? Mr Clegg replies that he wants to carry on.

Asked about a replacement for the Trident nuclear missile system, Mr Clegg says he believes Britain should remain a nuclear power but that the UK can "step down the nuclear ladder". Three submarines will suffice, he argues.