Despite portraying himself as Tony Blair's best friend, Mr Cameron, whose party supports trust schools and who has offered a lifeline in supporting the most controversial parts of the proposed legislation, was less than pally when he stuck the knife into the Prime Minister's sidekick and keeper of Old Labour's conscience.
Mr Cameron said: "The Deputy Prime Minister said, 'If you set up a school and it becomes a good school the great danger is that everyone wants to go there.' Do you agree with me that you shouldn't compromise with people who think that creating good schools is a bad idea?" he demanded.
Mr Blair replied: "I, of course, want to see more good schools, which is why I'm delighted to say that since this Government came to power the number of schools which have over 70 per cent of the pupils getting five good GCSEs is up from just over 80 in 1997 to over 500 today."
Mr Cameron asked: "Will you state categorically that the freedoms in the white paper - schools owning their own buildings, employing their own staff, developing their own culture - will you confirm all those freedoms will not be watered down and will arrive in the Education Bill?"
To Tory cheers, Mr Blair confirmed that he would not "water down" the plans. He said: "Yes, I will confirm that. I've been reading your speeches recently. I've read some on education as well, and I'm delighted to note that you now agree with us that there should be no return to academic selection. So, we are in favour of greater freedom for schools, no return to academic selection, and I therefore look forward to your support."
Mr Cameron said: "You'll have our support. But I love these lectures on consistency from you. Your first act as Prime Minister was to abolish grant-maintained schools, and your last act as Prime Minister is to bring them back again."
Urging him to get on with the education reforms, Mr Cameron prompted laughter by suggesting Mr Blair went into politics to "soak the rich and ban the bomb", but had ever since been "sucking up to the rich and dropping bombs". Later in the debate, Ben Wallace, Conservative MP for Lancaster and Wyre, asked Mr Blair: "Could you please tell the House the difference between a grant-maintained school and one of your new trust schools?"
To roars from the Labour benches, the Prime Minister simply told him:
"There will be fair funding and fair admissions, and there were neither in grant-maintained schools."