The Government last night played down calls to consider teaching black boys in separate classes to help them improve their school grades.

Trevor Phillips, chairman of the Commission for Racial Equality, said such a radical option may be the only way to stop so many black boys failing at school.

He also called for tougher action against black fathers, suggesting they could be denied access to their sons if they refuse to attend school parents' evenings.

But a spokeswoman for the Department for Education said segregation could have a "negative" impact and could stigmatise teenagers.

Figures published last month showed black teenagers continued to lag far behind their white classmates at GCSE, although there were signs the gap was narrowing.

Last year, only 35.7 per cent of black Caribbean pupils in England gained at least five C-grades at GCSE, compared with a national average of 51.9 per cent.

Mr Phillips told BBC1's Inside Out programme that many black boys were suffering from a culture where it was not cool to be clever.

"If the only way to break through the wall of attitude that surrounds black boys is to teach them separately for some subjects, then we should be ready for that," he said.

The department spokeswoman said the Government would want to look in more detail at the evidence behind Mr Phillips's comments.

"But we do have concerns over segregating groups of pupils," she said.

"Research suggests separating pupils in this way can have negative effects in terms of teacher-pupil expectations and can result in stigmatising and limiting young people."

But Sir Bill Morris, who has conducted an inquiry into racism in the police, said some form of intervention was necessary.

Sir Bill said: "This is a British issue and we need to find a British solution. We should have intervention."