A female British jihadist and a member of the ISIS has condemned David Cameron for 'waging wars' against Muslims, saying she wants his 'head on a spike'.

The 18-year-old, who is believed to be living in the ISIS stronghold of Raqqa in northeast Syria, said that she doesn't care if she is stripped of her citizenship.

She also hit out at the prime minister's plans to prevent British jihadis from re-entering the country, according to a report on Tuesday.

The development comes amid concerns that a growing number of young British women are leaving their families in Britain to join the jihadi cause in Syria.

The girl wrote on Twitter: 'In sha Allah (God willing) a day will come when David Cameron's head will be on a spike as he continues to wage war on the awilya (protectors) of Allah... and strike terror in the hearts of the kuffar.'

She added: 'I really do not understand why Britain is threatening to remove our citizenship like we care lool its actually quiet laughable.'