Johnson warns Labour colleagues not to attack Cameron on class

Alan Johnson, the only member of the Cabinet who never went to university, has warned Labour against engaging in the "politics of envy". Labour's mission should be to unite people of all backgrounds, and "pour fuel on the fire" of working-class ambitions, he said.

Although the Education Secretary confined himself to talking about children who are at school now, his remarks will also be seen as a warning to Labour not to make personal attacks on David Cameron and other Tory "toffs" central to their next election campaign.

People on the other side of the tactical argument want to attack the Tory leader for his privileged upbringing. Roy Hattersley, Labour's former deputy leader, has suggested that the photograph of Mr Cameron as a university student, dressed in the £1,000 outfit of a member of the elite Bullingdon Club, should be used in Labour's next election campaign.

But Mr Johnson, the front-runner in the race to succeed John Prescott as deputy leader, warned that "someone's class should neither provide a platinum card into the VIP lounge of life, nor a heavy burden weighing down on their back".

Mr Johnson fears that if Labour is seen attacking Tories for their expensive education, it will put off working-class parents who want an education system that gives their children a chance to rise up the social scale.

But he warned that changes in society generally are making working-class boys, in particular, less ambitious than they used to be.

In a speech to the Fabian Society, he praised the founders of the Labour Party for rejecting the "easier" option of stirring up resentment and anger in Victorian society. Instead, they took on the more difficult task of building an alliance across class boundaries against injustice.

"Labour is at its best tackling the poverty of aspiration, rather than engaging in the politics of envy. We've always believed in using the power of education to widen aspiration," he said

Mr Johnson, who worked as a postman for more than 20 years, warned that changes in family structure and employment patterns have made it harder for working-class boys to aspire to better themselves.

He said: "Working-class boys have traditionally defined their identity in terms of their job, their family and their responsibilities. Each has been hit by wider social and economic change.

"Within the working class lies a burning passion to better themselves, but social and economic changes are closing down many of the routes which they might once have taken. Education can overcome this."