Almost ten per cent of the Met's recruits are from ethnic minorities

The idea was put forward by the Metropolitan Black Police Association (MBPA), to make the force more representative of London's racial mix.

Such a plan would mean changing the 1976 Race Relations Act.

In 2002-03, 9.8% of recruits were from ethnic minorities, but by 2009 this must be 25.9% under government targets.

'Standards'

Martin Tiplady, the Met's head of human resources, told BBC London the force did not "stand a prospect of getting anywhere near the target", according to their current rate of progress.

A large number of ethnic minority staff, both officers and civilian workers, are leaving the organisation just two years after joining Leroy Logan, Metropolitan Black Police Association

But since 1998 the force has doubled the proportion of ethnic minority officers.

Mr Tiplady said if the Met were to use positive discrimination this will not mean a drop in standards.

"We follow nationally agreed recruitment standards. The law would need to change in order to allow us, to pursue positive discrimination.

"We would still require there to be a standard that is maintained, and then only then would we at that point give discrimination or priority to the black candidate," he said.

Met chiefs will meet the Commission for Racial Equality to ask for its advice and backing.

If secured it will seek the support of Home Secretary David Blunkett, according to the Guardian newspaper.

'Diverse organisation'

The target was set after the Met was labelled as "institutionally racist" by the Macpherson report on the police investigation into the death of Stephen Lawrence.

The black teenager was murdered in 1993 in Eltham, south east London.

The Met was called "institutionally racist" by the Macpherson report

Leroy Logan, chairman of the MBPA, told BBC News Online that the association had put forward the idea of positive discrimination to the Morris Inquiry.

Since January the inquiry has been investigating how internal complaints concerning ethnic minority officers are carried out.

Mr Logan said: "The police service can see the merit of positive discrimination. A large number of ethnic minority staff, both officers and civilian workers, are leaving the organisation just two years after joining.

"They are more likely to leave than their white counterparts. This isn't just a numbers game but about change. We've seen how positive discrimination for Catholic officers has helped the Northern Ireland Police Force.

"People aren't going to join unless they see a more reflective and diverse organisation. There are extra complexities that prevent ethnic minorities joining the force and achieving their full potential."

'By example'

Ray Powell, president of the National Black Police Association, said it would be useful in areas where there are a high percentage of ethnic minorities - some London boroughs have a 70-80% black population.

But he said coping with 'positive action policies' in the police force was already an issue, and people want to see ethnic minorities getting jobs in specialised areas and chief officer positions.

"The service can't manage the backlash from current policies. This new initiative might be perceived as a knee-jerk reaction.

"If we are to have any affirmative action, it should be on retention and progression, not recruitment. That would produce a knock-on effect, by example.