Athletes and officials are arriving at the Olympic Village, with 11 days to go until the London Games open.
Heathrow Airport is expecting its busiest day on record and on the main route out – the M4 – the first priority “Games Lane” is in operation.
Work is also starting at the lab which will conduct some 6,000 drugs tests.
Meanwhile, it has emerged police have had to deploy extra officers from nine UK forces at short notice to help with security work for London 2012.
This follows the news last week that 3,500 troops had been drafted in to plug gaps after private security firm G4S failed to recruit enough guards for the Games.
In the Commons, Home Secretary Theresa May answered an urgent question on Olympics security from shadow home secretary Yvette Cooper saying that it was “untrue” that ministers knew last year that there would be a shortfall in the numbers of security personnel they had been promised.
“G4S repeatedly assured us that they would overshoot their targets,” she said.
Mrs May said the government had taken immediate action after becoming aware of the shortage last Wednesday.
Metropolitan Police Assistant Commissioner Chris Allison said: “Whilst some of the activity police officers are undertaking was not anticipated, plans were put in place to allow us to do this.
“Forces are making sure they make the best use of their resources locally to do all they can to minimise the impact on local policing.”
The forces involved include Dorset, Surrey, Hertfordshire, Northumbria, South Wales, Strathclyde, West Midlands, Thames Valley Police, and Greater Manchester Police.
In Salford, only 17 of an expected 56 G4S staff turned up for work at an Olympic team hotel and front-line officers had been pulled in to cover, the chairman of the Greater Manchester Police Authority said.
G4S said measures were being taken that should lead to the withdrawal of officers from private security roles “over the coming days”.
by: Jon Kay