Britain's mainstream politicians united in condemnation of the BNP after the party won two seats in the European parliament.
David Cameron, the Conservative leader, said the result was "desperately depressing" and the main parties had to win back those who had voted for the far-right party.
"What the mainstream parties have to do is prove their worth, get on the doorstep, explain to people how we are going to take up their concerns, how we are going to respond to their issues," he said. "That is the way to beat these dreadful people."
The borders and immigration minister, Phil Woolas, vowed the government would not scapegoat immigrants. "Our shake-up of the immigration system is bringing better border controls, visa management, and citizenship policies that are managing migration and helping genuine immigrants to integrate better," he said. "The government … will at all times maintain its commitment to racial equality."
The communities secretary, John Denham, whose job includes promoting inter-ethnic harmony, told BBC Radio 4's World At One: "It is very important that we understand that the problem last night was more voters staying at home who might have voted to keep the BNP out, rather than their vote going up.
"But we have got to make it very clear that we want to hear what these voters are saying."
Jon Cruddas, the Labour MP for Dagenham, who has been at the forefront of Labour campaigning against the BNP, said Labour had failed to meet the concerns of many of its natural supporters about issues such as housing and immigration.
"There is a long-term legacy of us failing to bring people with us and deal with some of the issues that concern them, be they around housing or employment insecurity, or the recession, or immigration," he said.
"Since 2003-04 there's been extraordinary demographic change in this country and we have to acknowledge it, especially in poorer parts of the country."
The BNP's victories came in Labour strongholds in northern England, former industrial towns and cities blighted by the collapse of British manufacturing since the 1980s.
"I find it very disturbing," said Roy Hunjan, 70, a retired health worker from Birmingham. "They're trying to give a very different image but basically they're the same as the Nazi party. When the economy goes wrong, people look for a scapegoat like Hitler was looking at the Jews."
Analysts said the BNP would have little practical impact in Strasbourg. "Even with seats in the European parliament they won't be able to have a lot of influence," said Simon Usherwood of the department of politics at the University of Surrey. "They will still be too small to have any significant impact. And one of the problems with the far right is often they have trouble working together with other groups."
Others from the Labour party did not take such a relaxed view. Peter Hain, the newly appointed Welsh secretary, said: "It's a shameful stain on Britain that we now have racists and fascists representing our country. It is vital that everyone now isolates and confronts the BNP and works with United Against Fascism to defeat them."
Ken Livingstone, the former mayor of London, said: "The economic crisis and abuse of MPs' expenses have provided fertile ground for the extreme right. It is no surprise in these circumstances to see an electoral breakthrough for the BNP, a fascist party in Britain.
"The BNP claims to be a normal political party. In fact they are 21st-century Nazis. As in the 1930s, they exploit people's anxieties in an economic crisis to scapegoat minorities and ultimately threaten all our democratic freedoms."
