The Prime Minister warned that the Tories would tell every family in the land that Labour planned a tax rise of pounds 560 a year for each child taking A-levels.
Mr Brown last week proposed ending child benefit for 16- to 18-year-olds in full-time education qualify and putting the pounds 700m raised directly into their schooling.
Mr Major's attack came at Question Time after Tim Renton, a former Tory chief whip, endorsed his declaration that those who thought Britain could be a trading haven outside the European Union were living in "Cloud-cuckoo- land".
The Prime Minister's remarks in a speech to the Institute of Directors in London was intended to scotch talk of possible withdrawal from the EU.
But Mr Renton had another target. Pointing out that the original Cloud- cuckoo-land was "an imaginary city built in the air by the birds", he went on: "Would that not be a suitable destination too, for those who think they can vote Labour without seeing their personal and business taxes going sky high?"
Not only personal and business taxes, Mr Major replied. "It now seems that anyone who is ill-advised enough to encourage their youngster to stay on and take A-levels will lose pounds 560 of child benefit every year."
It was not just a question of the withdrawal of child benefit, because the benefit was a tax allowance, he said. "This is the direct equivalent of a tax increase of pounds 560 for every family with children taking A-levels."
Turning to the shadow Chancellor, he added: "It's no point in Mr Brown shaking his head - it's his policy, it's nonsense and we intend to tell every family in the land about it."
However, it is not just Tory scorn that Mr Brown has to worry about. Sixteen Labour left-wingers have signed a motion stating that the maintenance of universal child benefit is "an essential part of the welfare state". Though nominally addressed to the Government, the motion is in reality a shot across the bows of the shadow Chancellor.
Tony Blair, however, focused on the Prime Minister's difficulties over the Family Law Bill after 165 Tories, including four Cabinet ministers, voted to extend to 18 months the "cooling off period" before most couples can get a divorce. The revolt showed "the humiliating state to which Mr Major's authority has been reduced".
"I think most people have an increasingly clear view of his government," the Labour leader said. "This was a government Bill ... and this vote wasn't just about the amendment. It was fundamentally about the ethos of the Bill and the direction of the Conservative Party."
An angry Mr Major was called to order by Speaker Betty Boothroyd as he accused Mr Blair of being "deliberately misleading" - an unparliamentary charge. "I have made it clear that on the issues of fault and other issues of conscience this would be a genuinely free vote."
But Mr Blair persisted. The Prime Minister's real problem was that every member of his Cabinet had a future agenda but him. "And until he gets one and asserts it, this country will continue to suffer from the most feeble Government in living memory," he said.Reuse content