Up to 100 British children may have been born to Islamic State brides in Syria, sources have suggested, creating a huge security headache for the Government, as it seeks to strip dual national jihadists of UK citizenship.

Last week Sajid Javid, the Home Secretary, announced that he had revoked the British passport of former east London schoolgirl, Shamima Begum, a decision that her Bangladeshi father has now said he supports.

But the Government was forced to concede that her son Jarrah - who is just a week old - is a British citizen who has every right to return to the UK.

Around 150 British girls and women are thought to have travelled to Syria to join Islamic State of Iraq and the Levant (Isil), with almost all marrying and giving birth in the self-declared caliphate.

A further 50 older children were taken to Syria by their parents, but around a quarter of those are thought to have been killed.