If it’s in Hansard, then it must be true:

Sir Menzies Campbell (North-East Fife) (LD): What is the Prime Minister’s assessment of the sums wasted by fraud, error and overpayment in the tax credit system he set up three years ago?

The Prime Minister: It is very interesting that the leader of the Conservative party did not ask anything about the married couple allowance or tax credits and that it has been left to the leader of the Liberal party to pick up the baton. Tax credits are the most successful policy in removing child poverty in this country: 6 million families benefit from tax credits. Yes, there was computer error to start with, but it is being substantially reduced and the right hon. and learned Gentleman should admit that 600,000 children are not in poverty today because they are receiving tax credits.

Sir Menzies Campbell: But as the Prime Minister said on the radio this morning, there is still a long way to go. The truth is that the money wasted is heading towards £9 billion—£9 billion that could have been better spent. Behind that figure there are 2 million families whose lives have been made miserable by error and overpayment. Is not that the responsibility of the Prime Minister?

The Prime Minister: I can tell the Leader of the Opposition he knows what it means, saying a long way to go. Child benefit was £11 when we came into power; it will be £20 in 2010. The child tax credit was £27 and it is rising for the poorest families to more than £70, compared with £28 when the Conservatives were in power. We have done more through these measures to take children out of poverty than any previous Government in the past 30 or 40 years. The right hon. and learned Gentleman should be supporting the tax credit system, not condemning it.

It seems Mr Brown cannot help but offer Lib Dems a top job every time he sees one. I guess that’s the trouble if you read out the script you’ve carefully prepared for your reply to the Tory leader, and then forget who asked the question. And anyway, the Lib Dems are the only real opposition to Labour in Parliament.

But Gordon Brown has a point: why did David Cameron duck this issue today?