The Prime Minister is set to warn of the dangers posed, particularly to young people, by those who "quietly condone" Islamic State militants' extreme ideology.
David Cameron is also expected to highlight the role that families and communities can play in countering radicalisation, when he addresses a security conference in the Slovakian capital Bratislava later today.
He will argue that non-violent extremism plays a part in justifying the world view of jihadists.
His warnings come just days after 12 members of the same family, which includes nine children, went missing and after travelling to Turkey following a pilgrimage to Saudi Arabia. The three Bradford sisters and their children are believed to have travelled to Syria to join extremists.
Talha Asmal, 17, from Dewsbury, West Yorkshire, thought to have been the UK's youngest-ever suicide bomber, reportedly blew himself up in Iraq earlier this month.
Talha Asmal is thought to have been the UK's youngest-ever suicide bomber
The Prime Minister is expected to say: "The cause is ideological. It is an Islamist extremist ideology one that says the West is bad and democracy is wrong that women are inferior and homosexuality is evil.
"It says religious doctrine trumps the rule of law and Caliphate trumps nation state and it justifies violence in asserting itself and achieving its aims. The question is: how do people arrive at this worldview?
"I am clear that one of the reasons is that there are people who hold some of these views who don’t go as far as advocating violence, but do buy into some of these prejudices giving the extreme Islamist narrative weight and telling fellow Muslims 'you are part of this'."
"This paves the way for young people to turn simmering prejudice into murderous intent. To go from listening to firebrand preachers online to boarding a plane to Istanbul and travelling onward to join the jihadis."
Cameron will argue that there have always been "angry young men and women" who buy into supposedly revolutionary causes, but this cause is "particularly potent today".
Papers such as the Daily Mail led with Cameron's forthcoming speech this morning:
Friday's front page of the Daily Mail
People have had very mixed reactions to the news.
Some feel that Cameron is scaremongering by "blaming" Muslims.
Seems people will believe all sorts of lies when it comes to UK Muslims as long as it fits their prejudice, haters going to hate
— Martin O'Neill (@DrNostromo) June 19, 2015
Seriously #Cameron thats how you lead a country ? Anyway... All my support to the UK Muslims.
— Saâd Msaid (@Sky6Walker) June 19, 2015
The more Cameron tells UK Muslims that extremism is mostly their problem to fix, the harder it becomes to tackle collectively/effectively
— rachel shabi (@rachshabi) June 19, 2015
First immigrants, now UK Muslims... Scapegoating is Cameron's fav pass time I see.
— Ax (@AxVillion) June 19, 2015
While others have leapt to the Prime Minister's defence.
In his speech, Cameron will add: "I think part of the reason it’s so potent is that it has been given this credence.
"So if you’re a troubled boy who is angry at the world or a girl looking for an identity, for something to believe in and there’s something that is quietly condoned online or perhaps even in parts of your local community then it’s less of a leap to go from a British teenager to an ISIL fighter or an ISIL wife than it would be for someone who hasn’t been exposed to these things."
Cameron is due to emphasise the importance of being clear where responsibility lies, adding: "Too often we hear the argument that radicalisation is the fault of someone else."
He will continue: "That blame game is wrong – and it is dangerous.
"By accepting the finger pointing – whether it’s at agencies or authorities – we are ignoring the fact that the radicalisation starts with the individual and we would be in danger of overlooking many of the ways we must try to stop it at the source.
"We need to treat the causes, not just the symptoms."
Four of the missing children from the Bradford family who disappeared earlier this month pictured at the UK airport leaving for Saudi Arabia
The Prime Minister will say that, while everything will be done to help the police and intelligence agencies to stop people travelling to Syria, "we mustn’t miss the point".
He will add that the authorities "are not responsible for the fact that people have decided they want to go".
Cameron will outline what plans are already in place to "root out this poison".
Such measures include removing IS online propaganda, which has already seen 90,000 piece of material taken down since 2010.