Cameron makes his debut

David Cameron signalled a new approach to parliamentary debate today by using his first appearance at the despatch box as Conservative leader to offer Tony Blair his party's support.

Less than 24 hours after his election as successor to Michael Howard, Mr Cameron made clear he wants to make good on his promise to avoid "Punch and Judy politics" with a calm and measured performance at Prime Minister's Questions in the House of Commons.

Faced by a wall of jeers and calls of "resign" from the packed Labour benches, Mr Cameron chose not to go on the attack, but to assure Mr Blair of his party's backing for many of his proposals to reform schools.

If Mr Blair is ready to press ahead with radical education reforms, Tories will vote with him, freeing him from the threat of defeat at the hands of his own backbenchers, Mr Cameron told the Prime Minister.

The unusual approach was viewed by observers in Westminster as the start of an effort by the new Tory leader to drive a wedge between Mr Blair and his critics on the Labour backbenches.

By highlighting areas of agreement with the Prime Minister, Mr Cameron is expected to press his claim to be the true "heir of Blair" and to brand Chancellor Gordon Brown as the main obstacle to necessary reforms.

Flanked by his defeated leadership rival David Davis, 39-year-old Mr Cameron made clear from the outset that he wanted to present himself as a new style of Conservative leader.

He avoided the finger-pointing and accusatory tone employed at PMQs by his predecessors Mr Howard and Iain Duncan Smith, who watched on from the backbenches.

And he made clear he intends to blame Labour for the bear-pit atmosphere at the weekly Commons clash.

His voice almost drowned out by shouting from the Labour side, he broke off from his first question to say: "That's the problem with these exchanges - the chief whip on the Labour side (Hilary Armstrong) shouting like a child. Is she finished? Are you finished?"

But, despite his less confrontational approach, Mr Cameron did not deny himself the use of barbed comments directed at Blair and designed to highlight his own youth, telling MPs: "His approach is stuck in the past and I want to talk about the future - he was the future once."

Mr Blair said he was " delighted" by the new spirit of consensus on offer from the Conservative side.

But he was quick to pounce on what he regards as the new Tory leader's weak point - his promise to "share the proceeds of growth" between public service investment and tax cuts.

As Mr Cameron offered his support for education reform and a new treaty to halt climate change, Mr Blair demanded to know if he also supported the financial measures behind them.

Amid Labour cries of "Answer! Answer!", the Prime Minister asked Mr Cameron whether he would now reverse Tory opposition to Labour's programme of increased investment in state schools and the Government's Climate Change Levy on polluting industries.

Mr Cameron's aides later underlined his promise to back education reforms.

A senior aide said: "Tony Blair can be as bold as he wants to be. He doesn't have to worry about his backbenchers, he can get this through with Conservative support.

"The White Paper says schools should have control over admissions. Blair doesn't have to be timid about the White Paper. There is no need to make compromises with Labour rebels."