Nearly one in five British Muslims has some sympathy with those who have fled the UK to fight for IS in Syria.
The number among young Muslims aged 18-34 is even higher at one in four.
The figures emerged in our exclusive poll conducted after the Paris atrocities led by French and Belgian jihadis returning from the war zone.
Prominent Muslims said the poll was a wake-up call.
Labour London Mayor hopeful Sadiq Khan tells The Sun today: “It is clear that Britain needs to take its head out of the sand and act to tackle extremism and radicalisation at home.
“Tackling extremism is a challenge for everyone but I believe British Muslims have a special role to play.”
The survey’s findings show a clear majority of the 2.7 million Brits who follow Islam are moderate.
Some 38 per cent of those polled say Muslims should not have to condemn terror acts carried out by IS.
Omar Elhamdoon, of the Muslim Association of Britain, said: “When we do condemn the acts it is maybe indirectly saying we are taking responsibility, and owning the problem when it is nothing to do with us. They are not representing Islam.”
Shocked Muslim leaders slam backing for jihadis
Islamic leaders last night said any British Muslims who have sympathy with those who join IS have a “warped understanding” of the situation in Syria.
But the Muslim Association of Britain admitted any level of support is concerning.
It spoke out after an exclusive Sun survey found 19 per cent of UK Muslims do have some sympathy with those like barbaric Jihadi John who flee to Syria.
However, our poll shows that despite today’s alarming figures, levels of support are falling.
Research for Sky News in March before IS’s Paris and Tunisia atrocities found 28 per cent had some sympathy for young fanatics.
That is nine per cent more than now. The number who have no sympathy at all for jihadis has also risen from 61 per cent in March to 71 per cent today.
Omar Elhamdoon, of the Muslim Association of Britain, said after the figures were revealed: “Those who do have sympathy have a warped understanding of what is happening out there.
“We have heard of people going out to Syria, who have then returned. They have probably become disillusioned with what they have seen and missed the comforts of Britain. That is an assumption we make.”
Some 2.7 million Muslims live in Britain, the 2011 census says. If the poll reflected views across the country it would mean 500,000 have some support for jihadis.
Some 17 per cent in our poll said their religion is more important to them than being British.
Our survey also found 38 per cent, which would equate to more than a million people, blame the actions of the West, such as the invasion of Iraq, for IS’s attacks.
A further six per cent say the biggest cause is poverty and discrimination against Muslims.
Mr Elhamdoon was not surprised by the 38 per cent figure.
He said: “There are people who see what happens from Britain in other countries and they will be angered. Some of those then have a tendency to be radicalised.
“This could be radicalised by them going out to do something or just by having those feelings.”
Only 25 per cent of Muslims say it is IS leaders who exploit vulnerable minds who are most to blame for its reign of terror. And just 30 per cent say their leaders need to do more to condemn IS.
A small majority still say speaking out against bloodbaths such as Paris and the 7/7 attacks is their responsibility.
Bashir Chaudhry, chairman of the League of British Muslims, said that figure should be higher.
He added: “This is not in the name of Islam. This violence is killing people. This so called IS are a farce, they are destroying the peace of the world.
“In Islamic philosophy you cannot even take your own life, let alone someone else’s.”
- The poll was a telephone survey carried out by polling company Survation for The Sun, with a representative sample size of 1,003.