The backlog of unresolved immigration cases in Britain has grown to more than 500,000.
The Home Affairs Committee said that this could take 37 years to clear at present rates.
In its latest report into the system, the committee questioned whether splitting up the UK Border Agency would change anything.
In its last report, the committee said there were 11 separate backlogs totalling 320,000 open or unresolved cases in the immigration system.
Now the BBC reports it says there is a 12th backlog of 190,000 files called the "temporary and permanent migration pool".
This brings the total to more than 500,000, which committee chairman Keith Vaz MP said was "staggering".
However, it is understood the Home Office disagrees with the figure because it is not new and has been over-counted by 40,000.
The committee said the backlog had emerged during its first session with the head of a new service dealing with visa and immigration applications.
"We need new people at the top,'' Mr Vaz told the BBC. ''We need a change of culture, but more than anything else we need to give them the resources that they need to clear the backlog."