GCHQ head Robert Hannigan to resign for personal reasons

The head of GCHQ, Robert Hannigan, has announced he is to quit for personal reasons.

Mr Hannigan, who has been in charge at the Cheltenham-based intelligence unit since 2014, informed Foreign Secretary Boris Johnson of his decision.

In a letter to Mr Johnson he said: "After a good deal of thought, I have decided that this is the right time to move on and to allow someone else to lead GCHQ through its next phase.

"I am, like you, a great enthusiast for our history and I think it is right that a new director should be firmly embedded by our centenary in 2019.

"I am very committed to GCHQ's future and will of course be happy to stay in post until you have been able to appoint a successor."

Mr Hannigan said that leading the men and women of GCHQ was a "great privilege".

"I am proud of what we have achieved in those years, not least setting up the National Cyber Security Centre and building greater public understanding of our intelligence work," he wrote.

"I am equally proud of the relentless 24-hour operational effort against terrorism, crime and many other national security threats.

"While this work must remain secret, you will know how many lives have been saved in this country and overseas by the work of GCHQ."

Mr Hannigan said he had initiated the greatest internal change at GCHQ in 30 years, and it was now "well on the way to being fit for the next generation of security challenges to the UK in the digital age."

Mr Johnson said: "You have led the renewal of some of our most important national security capabilities, which we continue to depend on every day to save lives from terrorism and to protect our interests and values."

Mr Hannigan, 51, a married father-of-two, was previously director general of defence and intelligence at the Foreign Office.