And the winner is: The television debate, writes Political Correspondent John Hipwood. Last night’s third exposure of Gordon Brown, David Cameron and Nick Clegg in the West Midlands was sharper, marginally more illuminating than the other two, and really quite good fun.

And the loser was: The Prime Minister. George Osborne summed it up, describing Mr Brown’s performance as “unremittingly negative”, and his arguments “as tired as he looked”.

The Labour leader probably didn’t get a lot of sleep on Wednesday night after his brush with Gillian Duffy, but, by golly, he looked shattered. It’s amazing that he’s still standing.

The issue which earned Mrs Duffy the description “bigoted woman” from Mr Brown, immigration, sparked the most angry exchanges, especially between Mr Cameron and Mr Clegg.

Not for the first or last time during the 90 minutes, it was the Prime Minister who looked like the man on the sidelines while the Conservative leader concentrated on his Liberal Democrat opponent as his main challenger.

Time and again Mr Brown attacked Tory policies on taxation and spending cuts, and Mr Cameron’s response was calculated and destructive – he simply ignored him and got on with his own arguments.

Just occasionally, the Labour leader’s attacks would irritate his Conservative counterpart to such an extent that he would bite back.

“What you are hearing from Gordon Brown is very desperate stuff from a very desperate man,” he said at one stage. “He’s trying again to frighten people, and he should be ashamed,” was another observation.

Mr Brown had begun with a very brief reference to his Rochdale tragedy.

“There’s a lot to this job, and, as you saw yesterday, I don’t always get everything right. But I do know how to run the economy in good times and in bad times, ” he said.

After three 90-minute bouts, the nation is probably exhausted.

Mr Clegg is the clear winner if you take all three TV debates into account because he has turned the 2010 general election into a contest between three parties rather than two.

But last night it was the Conservative Party leader who looked the most prime ministerial.