Tony Blair last night faced an angry backlash over plans to cut child benefit from the parents of youngsters who persistently commit crimes or play truant from school.

Labour left-wingers and child poverty campaigners lined up to condemn the plan - warning it would penalise already disadvantaged families - after the idea was floated in a series of Sunday newspaper reports.

Tory leader Iain Duncan Smith dismissed the proposal as a cynical "gimmick" by ministers ahead of the English local council elections on Thursday.

Mr Blair, meanwhile, was reported to be facing a Cabinet rebellion, with Chancellor Gordon Brown, Deputy Prime Minister John Prescott and Work and Pensions Secretary Alistair Darling all said to be opposed to the idea.

Questioned about the scheme on TV, Mr Prescott was distinctly lukewarm, describing it as no more than a "possibility" and making clear that he had not been involved in the discussions.

Earlier however, Downing Street confirmed that the idea was being actively considered within Government.

According to reports, Mr Blair has been the main driving force behind the scheme.

The Prime Minister was said to have been "astonished" by recent figures showing that 80 per cent of truants caught in police sweeps of shopping centres were with an adult, often a parent.

If the scheme was implemented, it could cost a family with one child £15.75 a week in lost benefit, rising to £17.55 for a lone parent with one child, plus £10.55 for each additional child.

Education Secretary Estelle Morris said that the sanction would only be used against those parents who persistently refused to face up to their responsibilities.

But Labour MP Diane Abbott said: "All we would do is make some very poor women, and their other children, even poorer."

The plan was also condemned by the Child Poverty Action Group which said it was "short-sighted" and would compound the stress on disadvantaged families.