Britain will deploy an extra 1,200 troops to the London Olympics, the government has announced following a last-minute recruitment meltdown at the Games' private security contractor G4S.
The decision on Tuesday was taken at a cabinet committee meeting chaired by British Prime Minister David Cameron, just three days to go before the Games officially open with some 10,500 athletes taking part
The extra personnel, who were already standing by on 48 hours' notice, bring the total military deployment at the Olympics to 18,200 - 4,700 of whom have been called up to fill in the G4S shortfall.
Olympics minister Jeremy Hunt said that while the numbers of security guards being provided by the beleaguered G4S continues to rise, ministers wanted to "leave nothing to chance".
"Security staffing levels at venues have been kept under constant review," Hunt said.
"G4S numbers continue to rise significantly and we have every expectation that will continue to be the case.
However, ministers decided that we should deploy the additional 1,200 troops that were put on standby last week.
"On the eve of the largest peacetime event ever staged in this country, ministers are clear that we should leave nothing to chance.
'Safe and secure'
"The government continues to have every confidence that we will deliver a safe and secure Games."
The 1,200 troops on standby were at their regular bases, having been brought down from one week's notice to 48 hours.
G4S admitted earlier this month it could not provide the total 10,000 guards it had promised for the Games.
Paul Deighton, chief executive of London Games organisers LOCOG, said Tuesday's decision was taken to "absolutely de-risk any aspect of the operation.
"With three days to go, we just want to make sure this works without any worries at all."
He said he was hopeful that the numbers of G4S staff could rise from below 6,000 to 7,000 but "you can't be absolutely certain of anything with a temporary workforce.
"Therefore we want to substitute a temporary workforce with a permanent, reliable workforce that we get with the military."
Asked if even more troops could be called up, he said: "We now have the full military deployment to deliver these Games in just about any scenario, so I'm confident about that."
In a statement to the London Stock Exchange (LSE), G4S said it understood the decision.
"We have made very good progress in the last few days and, in line with the revised deployment plan submitted to LOCOG, currently have around 5,800 security personnel deployed at Olympic venues," it said.
"Significant numbers of candidates are now reaching the final stages of the training and accreditation process each day."
G4S has pledged to bear the costs of the extra troops, telling the LSE that their overall losses on the contract would remain within their estimate of $54 million to $78 million.
Of the 17,000 troops already on "Operation Olympics", around 11,800 are from the army, with 2,600-odd each from the Royal Navy and the Royal Air Force (RAF).
At peak times, around 11,000 personnel will be performing security duties at the Olympic venues across London and beyond.
By contrast, Britain has around 9,500 troops on duty in Afghanistan.