The chairman of the Home Affairs Committee, Keith Vaz, has said the problems that had arisen raise questions as to whether the staff G4S had managed to recruit were up to the job.
He told BBC News:
We do need to examine what is the workforce that is in place at the moment. Have they been properly trained?
Are they going to be able to communicate with those that arrive at the Games and are they qualified to do what they are supposed to do?
I hope this is an opportunity for Mr Buckles on Tuesday to come out with the facts, to be very clear, to be very open, to be very transparent with Parliament so that we can get to the bottom of what has happened."
More top news
An air steward notoriously blamed for starting the Aids epidemic in the US has been posthumously cleared of spreading the virus.
The Gangsta's Paradise singer was told if he is found with a single bullet on him in the next three years he could face jail.
Workers are also taking out payday loans and pawning their belongings just to get by, according to a survey by Unison.