The party, which is preparing for its biggest-ever electoral campaign, has chosen Sharif Abdel Gawad to fight Bowling and Bakerend ward in Bradford.

It describes Mr Gawad as a “totally assimilated Greek Armenian” whose grandfather, an Armenian Christian, claimed asylum in Britain.

But the posting of his name among the party’s list of candidates has caused uproar among members who believe that the party must field all-white representatives.

Workers at the party’s headquarters spent yesterday fielding angry calls from members who refused to accept Mr Gawad’s candidacy on race grounds, “even when it was explained that he was not a Pakistani or a Muslim”. There were calls for the regional organiser responsible for Mr Gawad’s selection to resign, and anger at party bosses.

In 2004 Nick Griffin, the BNP’s leader, tried to force through rule changes allowing non-whites to join the BNP. He backed down after widespread opposition.

Last night a spokesman said that members who refused to accept Mr Gawad’s candidacy had no place in the party.

But on white nationalist websites members were incredulous. “Is this some kind of wind up?” demanded one on the bulletin board Stormfront.

Another wrote: “I’m going to have a tough time explaining this on people’s doorsteps when I’m canvassing.”

Many were convinced that despite assurances, Mr Gawad was of Asian descent. One wrote: “I don’t give a stuff if he has ancestors that built the Taj Mahal, he ain’t British.”

Although a few thought the selection a “smart move” to improve the party’s image, they were outnumbered by members threatening to resign.

One read: “The BNP is the last bastion of hope for our people, they too have been let down if just anyone is allowed to join. Ethnics have every single opportunity afforded them, and now they even get to join the BNP. Just like immigration into this country, we were not consulted. When an ethnic wants to join, it should go to a membership vote. We’re the ones who do all the work, we should have a say.”

Another read: “No one is listening, and the worst calls I’ve had today are demanding a leadership challenge.”

The party will field 357 candidates on May 4.

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