Lord Coe, the chairman of the London 2012 Olympic organising committee (Locog), said today that he "could not rule out" asking for the current deployment of 17,000 to be increased. According to the Daily Telegraph, the MoD (unsurprisingly) has contingency plans for additional deployment. Senior military officers told the newspaper this week that they expect "up to 20,000" service personnel to be involved in the Olympic operation.

How the 17,000 was made up:

A total of 17,000 servicemen and women will ... be involved in the Olympics, including 11,800 soldiers, 2,600 sailors and marines, and 2,600 airmen.

Some 11,000 of these will be involved in the security of more than 30 sporting venues and some 70 non-competition venues, including car parks and hotels, while others will carry out specialist support roles including air security, search teams, communications and logistics.

Overall, a 23,700-strong security force for the Games will include a mix of military, private security guards and at least 3,000 unpaid London 2012 volunteers.