The wake-up call is made in a PAC report entitled 'Preparations for the London 2012 Olympic and Paralympic Games - risk assessment and management', which is released today (10 July).
The report says: 'There is a lack of clarity about how venues will be used after the Games, with the risk that designs fail to reconcile the needs of the Games in 2012 with those of subsequent users.
'Legacy plans for using the five new venues which will remain after 2012 should now be finalised, with ownership and responsibility for conversion and running costs resolved for each venue,' the report concluded.
Edward Leigh, PAC's Tory chairman, speaking in the Times, called for the ongoing management of the Games to be carried out with an 'iron hand'. He also said that it was worrying 'that strong arrangements for monitoring progress and managing risk were not in place.'
Download a PDF of the PAC report here .