The SIA is responsible for vetting all door supervisors, vehicle immobilisers and security staff. So after it emerged that the SIA were approving thousands of illegal immigrants to work as security guards there were obviously questions about the organisation.

A review has been commissioned by a non-departmental public body who have found a series of flaws in the SIA.

It revealed the organisation has had a heavy reliance on temporary staff and ‘lacked robust processes’ for allocating resources.

Thye also say that they need to work more closely with the police and the board and executives should provide ‘more leadership’.

It included 12 illegal workers approved for security jobs with the Metropolitan Police, including one guarding the Prime Minister’s car.

Some 3,000 have since proved their right to be in the UK but it emerged earlier this week that just 35 of the remaining 7,729 who had their licences revoked have been removed from the UK.

Chris Grayling , Shadow Home Secretary, said: ‘This report paints a worrying picture of mismanagement at an organisation that cleared thousands of people to work in sensitive security jobs in the UK even though they were illegal immigrants. ‘

‘The fact that the organisation is clearly still struggling, and that Ministers have so far only managed to deport 35 out of the thousands of illegal workers, gives rise to real concerns about what is happening.’