Home secretary Theresa May faced a storm in the House of Commons in response to the Olympics security shambles around the huge shortfall in staff numbers.

May was called to the house to answer urgent Labour questions on security for the games after it was revealed that an additional 3,500 troops would be required to plug gaps in staffing for security contractor G4S.

Despite the Opposition's incredulity that such a major shortfall was not noticed until so late, May remained defiant that the scale of the problem had not "fully crystallised" until Wednesday.

She revealed that some of the troops pulled into the games would have just returned from active service overseas, including Afghanistan, and would have to rearrange any planned leave.

Theresa May
The home secretary faced criticism in the house over Olympic security (Parliamentlive)

She would not be drawn on any action being taken on breach of contract by G4S, claiming that it was a LOCOG responsibility as it hired the company.

Shadow home secretary Yvette Cooper branded the situation "another huge Home Office shambles".

She said: "What does it say about the assurance processes that she [May] took that this problem was not noticed until two weeks before the games are due to start?"

Not simply a few volunteers short

She quoted May's comments on 9 July, when she told the house she was "confident our partners will deliver a safe and secure games".

She added that a shortfall of 3,500 was "not simply a few volunteers short" but was short by 25 percent and represented a breach of contract by G4S.

"Please get these security problems sorted out and stop letting everybody down," she said.

May explained that the government had "deliberately budgeted-in flexibility" to allow it to respond to any problems. The increase in troops at the games will mean that there will be 17,000 active during the event.

"[The troops'] deployment will have no adverse impact on other operations," she insisted, before making it clear that there was no specific terrorist threat made to the games.

She also claimed that the taxpayer would not be picking up any additional costs as the government was confident it would remain withing its £553m budget.

"We have the finest military personnel in the world," she said, before claiming that steps would be taken to ensure that no soldier was left out of pocket for any leave or events that they had planned for the weeks of the games.

Tickets for the troops

Thousands of tickets to the games, the Paralympics and the opening and closing ceremonies would also be provided to the armed forces.

May would not be drawn on the exact figures that were expected from G4S, who were contracted to provide trained security personnel to work alongside troops and volunteers for the games.

Jack Straw asked for the total number of trained staff and the total number of volunteers expected for the games. May said that 23,700 was the expected total number of security forces before telling the former home secretary to "do the maths himself".

Keith Vas, Labour's chair of the home affairs committee, voiced concerns about troops being exhausted as well as out of pocket, before calling for repercussions against the contractor.

"G4S has let the country down and we have literally had to send in the troops," he said.