Up to 13,500 military personnel will help to provide security at the London 2012 Olympic Games.
The Ministry of Defence has announced 5000 troops will support the police, up to 7500 will provide venue security and 1000 will provide logistical support.
They will be on hand across Britain to protect 150 venues and training sites.
In addition, there will be a 1000-strong contingency force ready for deployment in the event of an civil emergency.
The BBC reports the deployment will be larger than Britain's current military force in Afghanistan.
The Games security budget was revised last week from £282 million to £553 million.