Up to 2,100 part-time military personnel will be called out to work as part of the security force for the London 2012 Games, Defence Secretary Philip Hammond has announced.
The reservists will be part of the 13,500-strong military force, which is more than the 10,000 that were deployed to Afghanistan, who will guard the Games.
Some reservists will provide a range of specialist capabilities and expertise but the majority will be used to support the Olympic venue security operations.
The 2,100 personnel in line to work at the Games are just shy of the 2,300 reservists who have been called out annually for operations around the world since 2008.
At the peak in 2004, reservists made up 20% of UK forces in Iraq and 12% in Afghanistan. There are currently almost 600 reservists in Afghanistan, representing 6% of the deployed force. They back up the regular units and supply vital skills such as medical or niche logistical and communication expertise.
The overall 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 who will be used at the start of the security process.
An order was made in Parliament under section 56(1A) of the Reserve Forces Act 1996 to enable reservists to be called out for permanent service as part of defence's contribution to the safety and security of the London 2012 Olympic and Paralympic Games.
In a written ministerial statement, Mr Hammond said that call-out notices can then be issued to reservists, who have the necessary training, skills and availability, and employers, with the aim of giving 60 days notice to report for service.
The statement notes: "Both the reservist and overall defence contribution is on a similar scale to that deployed by other nations at recent Olympic Games and will contribute to ensuring a safe, secure and enjoyable 2012 Olympics."
The order is effective from February 16 to September 20, 2012.