SW1 speculation is in overdrive this morning over who will become the new Defence Secretary, now that Ben Wallace has officially submitted his letter of resignation. A handful of names are doing the rounds this morning. Grant Shapps, Liam Fox, John Glen, Jeremy Quin, James Heappey and Tom Tugendhat are the top contenders. Guido’s hearing a lot of chatter about Shapps, although given he is already a well-liked figure as Energy Secretary it would make the ri-shuffle more extensive than the PM appears to have an appetite for at the moment. John Glen is seen as a safe choice though Defence mandarins will be wary of a Treasury man. Liam Fox emerged as a surprise candidate last night in the Telegraph. Given he had to resign from that role once already, it would be a shock…

UPDATE: Shapps in Downing Street, announcement expected imminently…

UPDATE: Shapps confirmed.