No one has cracked GCHQ's Christmas card and there are only 2 days left

No one has cracked GCHQ's Christmas puzzle and there are only two days left, the British intelligence agency said today.

The card, which GCHQ director Robert Hannigan sent to contacts at the start of December, is designed to "exercise the grey matter" of participants over the holiday season.

Approximately 30,000 people have attempted the challenge, with about 1,500 making it to the final stage.

Hannigan said in a press statement on GCHQ's website today: "With a few days to go no one has cracked it all yet, so my one and only clue is: it's not as abstract as you think."

"What I hope the stages of the puzzle show is that to deliver our mission and keep Britain safe, we need people from all backgrounds, with all skills, who look at problems from every angle."

GCHQ is on the hunt for more staff after Prime Minister David Cameron announced the agency is hiring 1,900 more intelligence personnel to help fight terrorism.

The card was only sent to a select number of people on the spy chief's contact list but others can download the puzzle here.

The deadline for entries is January 31. Answers will be revealed in February.