The far-right British National Party could win its first seat in the European Parliament by claiming just 8% of the vote, Labour's deputy leader Harriet Harman will warn.
Ms Harman is expected to say it would be "shameful" for the UK to elect a BNP MEP in the June 4 polls, just months after the US elected Barack Obama as its first black president. She will warn that Labour's analysis of recent council elections shows the BNP winning and coming second in seats traditionally held by all three main parties from the North West and North East to the Midlands, London, Yorkshire and Essex.
Speaking to the Progressive London conference, Ms Harman is expected to promise that Labour will use the 2009 European Parliament elections to "draw a line in the sand" against the advance of the BNP, which she denounced as "a party of racial hatred".
The proportional representation voting system used for Euro-elections increases the BNP's chances of winning a seat, she will warn.
"In the North West, where Nick Griffin, the BNP chairman, is standing, Searchlight estimates they only need about 8% of the vote to break through into the European Parliament," Ms Harman is expected to say. "That would be shameful for Britain just as the US shows the way forward by electing an inclusive, progressive president."
And she will add: "The BNP threat cannot be ignored. A new Labour analysis of council elections shows that even where they are not winning they are coming second in areas which are Labour, Liberal Democrat and Tory-held. Their poison is spreading. They are winning and coming second in the North West, the North East, the Midlands and London - from Yorkshire to Essex.
"Labour will, with a vigorous door-to-door campaign, not allow the BNP to peddle their pernicious lies that people have been 'abandoned by Labour'. It is Labour on the doorstep which will show this to be false and the run-up to elections on June 4 will be seized as an important opportunity to do this."