An additional 1,200 troops have been put on standby to cover more G4S security shortages during the Games. The Culture Secretary, Jeremy Hunt, announced yesterday that the military would be placed on 48-hour notice to step in.
Such action could bring the total number of troops at the Games to more than 17,000.
"As we have said, we must prepare for every contingency," Mr Hunt said after a meeting yesterday afternoon with officials from the Home Office, the Ministry of Defence and the Department for Culture, Media and Sport. G4S executives also attended the meetings with Government officials.
The G4S scandal prompted the Labour leader, Ed Miliband, to call into question plans to outsource police services to private companies such as G4S as it emerged yesterday that the Home Office and police still hold nearly £600m of contracts with the security firm.
Theresa May, the Home Secretary, detailed Home Office and police contracts with the company while responding to a written question from Labour's Keith Vaz, chairman of the Home Affairs Select Committee.
Her letter revealed that G4S holds contracts worth £301.4m with the Home Office. Services provided include running immigration and removal centres and an asylum accommodation centre for the North-east. The contracts expire between next year and 2017.
Police contracts with G4S total £283.8m and include a 10-year, £229.7m deal with Lincolnshire Police. The firm also runs "custody suites" for Lancashire, South Wales and Staffordshire police forces and provides forensic medical services to 11 county forces, including Essex, Hampshire and Norfolk.
Mr Miliband urged the Government yesterday to rethink plans to outsource more police services to private companies after G4S failed to meet its security target for the Olympics.
He said: "We are not getting the reassurance we need that core policing functions will not be privatised: there is a complete lack of oversight from the Home Office."
Mr Miliband said it "beggared belief" that G4S was trying to keep a £57m fee for Olympics security. But he refused to call for the resignation of Nick Buckles, the chief executive of G4S.
Yesterday, three chief constables met for talks as they came under mounting pressure to scrap plans to allow G4S to run "backroom services" in Cambridgeshire, Hertfordshire and Bedfordshire.