Mainstream political parties must work together to make sure Britain does not suffer the same outcome as France

Gurbux Singh CRE chairman

Conservative leader Iain Duncan Smith said extremists had to be opposed, but he warned the media to be careful about giving them the "oxygen of publicity".

Meanwhile, Home Secretary David Blunkett said the signs across Europe were dangerous but any extremist threat could be defeated.

'Genuine fears'

The far-right's advance in France is being blamed partly on concern about asylum, crime and immigration.

Mr Blunkett said it was critical to listen to people's concern and produce clear policies to deal with them.

"We can see off those who would exploit those genuine fears in order to create hatred and prejudice," he added.

Gurbux Singh urges parties to work together against racism

That message echoed the analysis of former cabinet minister Peter Mandelson, who said the French left, unlike Labour, had made the mistake of ignoring populist issues like asylum and crime.

Prime Minister Tony Blair is due to speak to incumbent French President Jacques Chirac on Tuesday.

Earlier, Jack Straw told BBC News the prominence in France of a party "that peddles such hate" was of "profound concern".

Unity call

That followed Mr Singh's warning, issued in an open letter to Mr Blair, Mr Duncan Smith and Liberal Democrat leader Charles Kennedy.

I don't think we should be complacent - I think we should be very much on alert

Rt Rev David Smith Bishop of Bradford

"We too face the threat of far right-wing groups trying to seize the political momentum, capitalising on ordinary people's dissatisfaction with mainstream politics," said Mr Singh.

"At the local government elections, mainstream political parties must work together to make sure Britain does not suffer the same outcome as France.

"The alternative will lead to a fracturing of our society, further dissatisfaction and unrest, and at worst, mayhem and chaos on our streets."

Mr Singh said the mainstream parties needed to work to build links between communities and engage voters on issues like poor housing, unemployment and education, rather than tougher immigration and asylum policies.

"The first step has to be the main parties working together to present a united front against racism, xenophobia and the politics of disunity," he said in his letter.

Apathy fears

Fears were raised that the British National Party could make gains in targeted towns after a new survey suggested that the turnout in 2 May's local elections in England could be an all-time low.

The party is putting up 68 candidates while 5,889 councillors will be elected nationwide.

BNP leader Nick Griffin told BBC News Online: "We were looking odds on to win a number of seats anyway and the fact the Le Pen question has raised the profile of our issues can only help."

'Do not panic'

The Guardian/ICM poll predicted that only 25-26% of voters will take part in the 2 May elections.

Meanwhile, the Rt Rev David Smith, Bishop of Bradford, where there were riots blamed on racial tensions and inner-city deprivation last year, said the French result was not "an occasion for panic".

"I am rather grateful that we have had this current warning in advance so that people who want a decent country to live in can avoid what has happened in France," he said.

Right-wing extremists did "turn up" in cities like Bradford and cause more trouble than their numbers, said Mr Smith, who warned against complacency.