BNP leader Nick Griffin has insisted he was "not a Nazi" during his first appearance on the BBC's Question Time.

BNP leader Nick Griffin has insisted he was "not a Nazi" during his first appearance on the BBC's Question Time.

The political discussion programme was recorded as anti-fascist campaigners protested outside Television Centre.

Mr Griffin was booed at the start of the recording and accused of having "poison politics" as he was attacked by fellow panellists and the audience.

He said he had been "demonised" and repeatedly denied sayings things which have been attributed to him.

The BBC has defended the invitation to the leader of the anti-immigration party to appear on the programme, saying it had a duty to be impartial.

During the show the panel covered topics including whether it was fair for the BNP to use images of Winston ChurchillWinston Churchill in their campaigns.

Justice Secretary Jack StrawJack Straw said what distinguished the BNP from other parties was that other parties "have a moral compass", adding: "Nazism didn't and neither I'm afraid does the BNP."

Mr Griffin, who said his father had been in the RAF during World War II, said he had been "relentlessly attacked and demonised... I am not a Nazi and never have been".

Mr Griffin repeatedly denied he had said many of the things he had been quoted as saying including a quote attributed to him in the Mail on Sunday that Adolf HitlerAdolf Hitler went "a bit too far".

He claimed his efforts to change the BNP meant he was unpopular with the far right. "There are Nazis in Britain and they loathe me," he said.

He admitted sharing a platform with former Ku Klux Klan leader David DukeDavid Duke - but claimed he had been trying to win over "youngsters" Duke was trying to "lead astray".

But Mr Straw said when anybody put a specific quotation to Mr Griffin he tried to "wriggle out of it".

Conservative frontbencher Baroness Warsi said Mr Griffin was "a thoroughly deceptive man".

Asked whether a misguided immigration policy had fuelled the BNP's popularity Mr Straw said he did not think it had and said he thought the BNP had been boosted by discontent with the main parties over issues like expenses.

But Baroness Warsi said politicians had a responsibility to take on the BNP on the issue of immigration: "Many people who vote for the BNP are not racist and therefore what we have to do is go out and say to these people as mainstream political parties we are prepared to listen."

While the programme, which is being broadcast at 2235 BST, was being recorded the anti-BNP protest continued, with the whole West London BBC building "locked down" for more than an hour and the road closed.

The Metropolitan Police say six protesters were arrested and three police officers injured in the protests.

Mr Griffin accused the protesters of "attacking the rights of millions of people to listen to what I've got to say and listen to me being called to account by other politicians".

But Weyman Bennett from Unite Against Fascism accused the BBC of "rolling out the red carpet" to Mr Griffin and said his appearance on the flagship discussion programme "will lead to the growth of a fascist party" and promote violence against ethnic minorities.

The crowd had been gathering at the main gates of TV centre in West London since mid afternoon. At about 1630 BST security guards opened a gate to let a car into the front car park about 25 people rushed forward and jumped over the barriers, one of which broke, and ran towards the building.

There were also protests outside BBC buildings in Bristol, Liverpool, Nottingham, Glasgow, where security staff and police officers stopped them from entering the building, and Belfast.

Earlier on Thursday BBC director general Mark Thompson said it was up to the government to ban the BNP from the airwaves if it felt Mr Griffin should not be allowed to take part in Question Time.

Some high profile Labour politicians - including cabinet ministers Peter HainPeter Hain and Alan JohnsonAlan Johnson - have said they opposed the BBC decision to allow the anti-immigrant party a place on Question Time.

But Prime Minister Gordon BrownGordon Brown said it was a matter for the corporation and he did not want to interfere with it, while Culture Secretary Ben Bradshaw said that most of the cabinet did not share Mr Hain's view.

Mr Byford had earlier defended the BBC's decision to invite Mr Griffin, whose party gained its first Euro MPs this year, on to the flagship political programme.

He said: "They should have the right to be heard, be challenged, and for the public who take part in Question Time and the viewers to make up their own minds about the views of the BNP. It's not for the BBC to censor and say they can't be on."