The first poll following Nick Griffin's controversial appearance on Question Time has found more than a fifth of voters would now consider voting BNP.
Taken in the hours after the show, the YouGov poll for The Daily Telegraph found 22% of voters would seriously consider voting BNP in a local, general or European election.
Two thirds said they would never vote BNP under any circumstances, with the rest unsure.
More than half of those questioned said that they agreed with the BNP, or thought the party had a point, in wishing to speak up for the interests of the indigenous, white British people.
This included 43% who said that while they shared some of its concerns, they had no sympathy for the party itself.
Some 12% said they completely agreed with the BNP and supported the party's decision to speak up, while 38% said they disagreed totally with the party's political outlook.
The figures are based on a sample of 1,314 electors across Britain interviewed online from October 22-23.
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A BBC spokesman said: "We have been very clear in setting out our reasons for having Nick Griffin on Question Time.
"The BBC's obligation is around due impartiality. It is not our job to comment on the ebb and flow of opinion polls."
Mr Griffin's debut appearance on the show sparked uproar, with angry scenes outside BBC TV Centre in west London as nearly 1,000 demonstrators protested.
He has said he is to make a formal complaint to the BBC about his treatment on the panel, which he believed had been deliberately "twisted" in order to focus on him and his party's policies, leaving him to face a "lynch mob".
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