G4S and Olympic security staffing: Lord West
12 July 2012 Last updated at 14:52 BST
Former security minister Lord West said the news that G4S was short of Olympic staff was "surprising and worrying".
He said it was "too close to the games" for the firm to make the announcement, but the firm had been struggling to vet people for some time.
Home Secretary Theresa May said security will not be compromised after it emerged that 3,500 extra troops would be needed. The government only found out on Wednesday that contractor G4S did not have enough trained staff.