Security and Counter-Terrorism Minister Baroness Neville-Jones has resigned after reportedly clashing with Home Secretary Theresa May.

Neville-Jones, 71, announced her move in a letter to the Prime Minister that offered no hint of what lay behind her sudden departure beyond offering Prime Minister David Cameron ideological support and noting that she informed the Government of her wish to leave some time ago.

“I have also been able to contribute to the essential rebalancing of security and liberty in the review of counterterrorism powers, the replacement of mistaken multiculturalism by an integration strategy which I hope will embed itself as a central feature of the Big Society, and to the redirection of the Prevent strategy which is nearing completion,” she wrote.

Neville-Jones will now move to the post of Special Representative to Business on Cyber Security and be replaced in her job by another peer, ex-Tory MP and Education Minister, Baroness Angela Browning.

Not even a year into her job, the loss of Neville-Jones, apparently of her own volition, will be seen as an embarrassment for the government no matter that she was not seeing eye-to-eye with her boss, May.

The nature of the fall-out probably has more than one element to it. The Daily Mail newspaper reported that she was disappointed to have been passed over for the role of National Security Advisor, handed to Sir Peter Ricketts.