Former Home Secretary David Blunkett has called for a radical change of strategy to oust extremist Islamic groups, and suggested the government's current strategy may have inadvertently supported them.

Speaking at the Board of Deputies on Sunday, Mr Blunkett openly criticised Prevent, the UK's anti-radicalisation strategy, which has spent much of £140m to fund activities of moderate Muslim groups.

He said the next home secretary needed to address "who it is that you are funding, assisting and liaising with. We've got to go out of our way to fund stopping [extremist groups], and not fund facilitating them."

Mr Blunkett also said he supported banning radical groups when asked about lack of action to proscribe the virulently anti-Zionist group Hizb-ut-Tahrir.

"The fear within government is always about breaking up these groups into smaller and more difficult to deal with groups. I think that it is a difficult argument. My instinct is to try to move rapidly where a threat can be ascertained."

Addressing 70 deputies in the chamber of Sheffield Town Hall, the city where Mr Blunkett is contesting his parliamentary seat, he acknowledged the difficulty of backing a single representative of the Muslim community.

"With the Muslim Council of Britain, whether they really represent the voice of moderate Muslims is a very difficult question. On one hand it [backing the MCB] is being benevolent to those people who are of goodwill, and on the other it is trying to tell them who can speak for them."

Election issues dominated remarks by Board president Vivian Wineman, who defended the deputies' request for the Labour Party to consider withdrawing candidates Martin Linton and Sir Gerald Kaufman over apparent antisemitic comments.

But Mr Wineman rejected a call to protest over the use of parliamentary buildings for the meetings where the comments were made; he said that "protesting to stop certain people speaking in a certain place would mean we risk losing our credibility".