The post-party conference season’s Annual Karaoke Showdown is in full swing: competition is hotting up.

Ed Balls has already done a hip-swinging Elvis rendition of “A little less conversation” and he’s promised to wheel out Greased Lightning so he can bring out his signature hand move from the Commons.

Theresa May raised a few eyebrows with The Police’s “Englishman in New York” – chuntering Labour backbenchers can’t quite believe she’s capable of irony.

Persuaded against Coldplay’s ‘Yellow’ at the last minute (too close to Cameron for comfort) a black-shirted Nick Clegg has sung a gravelly “Walk The Line”. When he tried to crowd surf off the stage, Ed Davey had to save him. What a hero.

But as the night draws on, it’s time for the big guns.

Flushed with the success of a tolerable conference speech, David Cameron steps into the spotlight.

The big brass notes begin – and as Tory frontbenchers squeal appreciatively, he launches into Tom Jones’ biggest tune. Pointing at Ed Miliband, he booms, “You can leave your shirt on!”

Energetic Ed follows up with Vanilla Ice’s hit “Ice Ice Baby” – it fails to reach the giddy heights of his original energy price freeze promise.

The judging panel are less than impressed – although the scores would have been different if chief judge Paul Dacre had turned up.

If only it was as easy to rate our politicians’ energy performances with an X Factor style buzzer – although if that was the case, there wouldn’t be a winner.