David Cameron pledges £5m for groups tackling extremism
Groups trying to root out the "poison" of extremist ideology in British communities will be supported by £5m of funding, David Cameron has said.
The prime minister said the money for campaigns and charities this year would help prevent the "seed of hatred being planted in people's minds".
The government's counter-extremism strategy will be launched on Monday.
The Muslim Council of Britain said there needed to be "clarity of purpose" in government policy.
Mr Cameron has previously criticised the "passive tolerance" of extremism, at the Conservative Party conference.
The £5m funding this year will be used to "build a national network of grassroots organisations", Downing Street said.
There will be practical support to expand the "reach and scale" of groups and promote "credible alternative narratives" to extremist propaganda, which could include social media training and technical assistance with websites.
Downing Street cited research from counter-extremism think tank, the Quilliam Foundation suggesting the militant Islamic State (IS) group produces 38 unique pieces of propaganda a day.
Mr Cameron said: "We need to systematically confront and challenge extremism and the ideologies that underpin it, exposing the lies and the destructive consequences it leaves in its wake.
"We have to stop it at the start - stop this seed of hatred even being planted in people's minds and cut off the oxygen it needs to grow."
He said the counter-extremism strategy will target "violent and non-violent" extremism, "actively support" mainstream voices and address the "segregation and feelings of alienation" that provide "fertile ground" for radical ideologies.
It is expected to include closer working between internet firms and police to remove online propaganda, using systems employed against child abuse images.
There will also be a crackdown on extremism in prisons and universities and incentives for schools to integrate pupils better.
"At the core [of the strategy] is building a national coalition of all those individuals and groups who are united in their determination to defeat extremism and build a more cohesive society," Mr Cameron said.
In a statement, the Muslim Council of Britain said: "Is this new policy initiative about tackling alienation, or seeking more securitisation?"
It said the former required "long-term capacity building and empowerment of Muslim civil society organisations", while the latter is "about preventing criminality and enforcing the law".
"To lump both in one programme of action is not logical," it said.
"We hope that funding will be distributed in a transparent way with clear measurable goals to tackle all forms of extremism."
The head of the Quilliam Foundation, Haras Rafiq, told the BBC that the fund, if it was well spent, could make a difference.
But he said money had been used unwisely in the past including on groups hosting samosa parties or printing t-shirts saying "I love Allah."
The Metropolitan Police's Counter-Terrorism Internet Referral Unit has removed more than 110,000 online pieces of extremist propaganda since 2010 and more than 38,000 pieces so far this year.
At least 700 people from the UK have travelled to support or fight for jihadist organisations in Syria and Iraq, British police have estimated.