ON THE way out of the House of Commons chamber following Prime Minister’s Questions this afternoon, David Cameron said to Ed Balls across the despatch box: “You were quiet today!”

Nothing ususual with that, you might say. After all, Ed has been known, occasionally, to have been rather – shall we say, enthusiastic? – in his support for the PM at these sessions. And today he wasn’t, hence Dave’s remark.

What was unusual about the quip is that twenty minutes earlier, as Dave was getting his backside roundly kicked up and down the gangway by the Clunking Fist, he responded to Labour heckles by pointing to Ed and shouting: “It is not just Back Benchers, Mr. Speaker – the Secretary of State for Children, Schools and Families is up to his old tricks again!”

Now, given that Ed had deliberately avoided twitching a muscle as he sat there on the Treasury bench, this was unexpected. And Cameron’s words at the end of the encounter confirmed that even Dave knew Ed had been on his best behaviour.

So why did the ‘Leader’ of the Opposition accuse the Children’s Secretary of being “up to his old tricks again”?

Simples: it was written down on the notes in front of him.

It didn’t matter that the accusation was falsely made – the TV audience would simply have assumed Ed was mooning him or whatever. It was on Dave’s notes, so he had to say it, regardless of whether it was justified.

Prime Minister-in-waiting, eh?