At least 4,000 illegal workers have yet to be banned from taking security jobs, despite the passing of a deadline set by Home Secretary Jacqui Smith.
Jacqui Smith revealed the figures last month in the Commons
On 13 December she said 11,100 people were being warned their Security Industry Authority (SIA) licence to work would be revoked in 42 days.
Of these, 6,653 were known to be working illegally in the UK and 4,447 were suspected of doing so, she said.
But although the 42 days is now up only about 2,700 licences have been revoked.
The SIA said the process was "ongoing".
The figure of 2,700 includes British nationals who have lost the right to work in the security industry because of criminal or improper behaviour since the SIA started in 2003.
The actual number of illegal workers who have lost their licence is likely to be lower because many have more than one licence, such as for working as a security guard and monitoring CCTV.
Ms Smith said a "significant proportion" of those with a question mark over them may yet prove they were legally able to seek work.
An SIA spokesman said: "We are still working through the names. It is an ongoing process.
"We are updating the register all the time, but there are a lot to work through."
Shadow home secretary David Davis laid the blame firmly with the government.
"Despite the serious threat posed by this shambles, the government have shown trademark complacency in dealing with it," he said.
"This shows they are part of the problem, not the solution."
The month before Ms Smith's announcement ministers thought only 5,000 people had been wrongly cleared to work in security.
Prime minister's car
The problem emerged after an enforcement operation in April discovered 44 people working at a security company who did not have the right to work in the UK.
Twelve had been sub-contracted to a company that provided staff to guard locations under Metropolitan Police contracts.
Others were employed at ports and airports, and one man had been guarding government cars including the prime minister's.
The SIA was set up to vet applicants for security jobs, and allows those who are successful to work on pub and club doors as well as in sensitive security posts.
An SIA licence shows a successful applicant has undergone training, plus identity and criminal record checks.
The responsibility to prove someone is entitled to work in the UK rests with employers.
Since 2 July the SIA has introduced new immigration status checks to provide a "double lock" on illegal working.