A ban on members of the far-right British National Party serving in the police was in prospect last night after the proposal from David Blunkett, the Home Secretary, was backed by the Metropolitan Police.
The intended crackdown follows claims from a BNP councillor that there were up to 12 party members serving with West Midlands Police. Concerns about racism in police ranks were heightened after an undercover BBC journalist exposed racism at a police training college in Cheshire last month.
Sir Ian Blair, Deputy Commissioner of the Metropolitan Police, said he backed plans for the instant dismissal of officers found to belong to the far-right party. He said he would talk to other police chiefs, and the Police Federation, to agree a voluntary national ban on the BNP because it was "such an unpleasant organisation".
He told BBC Radio 4's PM programme: "You cannot be a member of the BNP and discharge your duties properly as a police officer."
Mr Blunkett admitted he could not force chief constables to remove BNP members from their ranks, but would fully support those who did. "I do not believe it is tenable for a member of the British National Party to be a police officer in this country," he said.
The Home Secretary said he believed they could not pass new "diversity tests", which require police recruits to prove they will treat all members of the public fairly whatever their ethnic background.
"What we are addressing is deep-seated racism, and being a member of the British National Party is an indication not only of their views, but of their willingness to participate in a racist party.
"I believe, and I am prepared to work with the chief constables on this, that there is automatic, prima facie evidence that that person would not be able to pass the assessment that has been put in place."
At the moment, there is no automatic ban on political activists joining the force, but applicants must declare any political party membership prior to recruitment. In addition, officers are barred from taking an active role in politics or "any activity which is likely to interfere with the impartial discharge of his or her duties, or which is likely to give rise to the impression among members of the public that it may so interfere".
A spokesman for the Association of Chief Police Officers backed the Home Secretary's comments. He said: "The police service abhors any racist or other type of inappropriate behaviour in its members and will take all necessary steps to identify and root out any officers exhibiting such traits."
The BNP said in a statement: "We have an appreciable number of members who are serving with other forces throughout England and Scotland. This should not come as a shock; policemen and women have the same concerns about the future of the country as those in other walks of life."
The Home Secretary is also considering a widespread shake-up of police organisation, in which the smallest county forces in England and Wales could be merged.
A Home Office consultation document said the time had right to consider whether the current structure of 43 forces, which has existed for almost 30 years, was "the right one for today's and tomorrow's policing needs", and that larger "strategic" forces would be more suited to modern crime patterns.
Constabularies such as Warwickshire, Cumbria, Bedfordshire and Dyfed-Powys could be under threat. The City of London force could be incorporated into the Metropolitan Police and the British Transport Police could vanish. The Home Office paper suggested forming more "lead" forces, which could be called in to direct investigations into such crimes as murder, complex fraud and internet paedophilia. It also suggested that more roles could be handed to civilians to free more police for frontline duties.