Chancellor Gordon Brown yesterday poked fun at Witney MP David Cameron for his public school background.

But the Conservative leadership hopeful hit back, observing that Prime Minister Tony Blair was privately educated too.

Mr Brown sized up the field of Tory leadership contenders in his keynote speech to the Labour Party conference in Brighton, dismissing it as an "old boys' network" and singling out Mr Cameron for his Old Etonian roots.

He dismissed the credentials of Ken Clarke, Malcolm Rifkind and David Davis for being tainted by "old Conservative" values.

He made clear that he was not afraid of any of his potential Tory counterparts and dismissed them one by one -- although he accepted that 38-year-old Mr Cameron, who is set to officially launch his leadership bid on Thursday ahead of his party's conference in Blackpool, was the only new face among the candidates.

Mr Brown, the son of a Presbyterian preacher who attended Kirkcaldy High School, a comprehensive in Fife, mocked the privileged background of Mr Cameron, who was educated at Eton and Oxford University.

He said: "What of the Conservatives? They know that to make the public forget the miseries of the pre-1997 years they need new faces, modern ideas, a fresh start, a clean break.

"And who have emerged as the new faces? Kenneth Clarke, former Tory chancellor, Malcolm Rifkind, former Tory foreign secretary, David Davis, former Minister for Europe, Liam Fox, former Foreign Office Minister. And David Cameron, the only new face, is an old Etonian," Mr Brown added, to laughter around the conference hall. "Today's Tory Party is simply the same old rerun of the same old boys' network."

Mr Brown went on to scoff at the talents of the new generation of so-called Notting Hill Tories, of which Mr Cameron is the most prominent.

He predicted the swift political demise of George Osborne, the shadow chancellor and one of Mr Cameron's closest colleagues.

He said: "Since 1997 the Tories have had seven shadow chancellors -- I remember them well, most of them, and I look forward to welcoming the eighth.

"With the current one they made a virtue of skipping a generation -- on the evidence so far they should probably skip another one."

But Mr Cameron relished a potential dispatch box battle with Mr Brown, declaring "Bring it on."

He told the Oxford Mail: "I thought we lived in a meritocracy where people were not judged on their backgrounds -- this is just another example of Gordon Brown judging people on the basis of where they went to school.

"If he is saying that people will be judged on where they live and their background it sounds like a giant social experiment to me.

"I imagine he said the same things about Tony Blair -- seeing that he was privately educated.

"Everyone knows we need to reform public services and yet he is the one doing all he can to stand in the way of those reforms.

"Frankly I'm not bothered what Gordon Brown says. I say, bring it on."