The Daily Star's FREE newsletter is spectacular! Sign up today for the best stories straight to your inbox Sign up today! Thank you for subscribing See our privacy notice Invalid Email

Defence Secretary Michael Fallon last night said the jihadis had posed a “very direct threat to this country”.

And he vowed those detained would be “brought before the courts”.

IS is a banned terror organisation and being a member is a crime, which carries a maximum 10 years in jail.

Intelligence experts are monitoring the movements of 500 Brits who travelled to Syria and Iraq to join the terror network.

But it is the first time that it has been revealed so many of them have slipped back into the country.

Some of the Brit jihadists in Syria are known to have contacted the UK authorities asking if they can come back after being shocked by the violence displayed by IS. Yesterday House Of Commons leader William Hague, 53, warned of a “mushrooming” threat from IS as more trained fighters may now try and head back to Britain to dodge an aerial bombardment.

Mr Fallon, 62, told BBC Radio 4’s The World This Weekend: “We have toughened up now on the issue of passports and the watch on our ports and airports for returning fighters.

“Over 60 returning fighters have now been arrested. There are continuing threats to this country from returning fighters.”

Mr Fallon revealed six Brit Tornado GR4 fighter jets from RAF Akrotiri in Cyprus were now flying daily armed surveillance missions over Iraq.

Meanwhile David Cameron, 47, insisted airstrikes were “part of a comprehensive strategy”.

The PM said: “When you face a situation with psychopathic terrorist killers in Syria and Iraq, who have already brutally beheaded one of our own citizens, who have already launched and tried to execute plots in our own country to kill and maim innocent people, you have got a choice.

“We can either stand back from all of this and say ‘This is too difficult, it’s too complicated, let’s let someone else try to keep our country safe’.

“Or we take the correct decision to say ‘Let’s have a full, comprehensive strategy.'’’