The Home Office has come under fire in a critical report into the country's immigration system.
The Public Accounts Committee found that 50,000 failed asylum seekers have gone missing in the UK since 2012, while 175,000 are still awaiting removal from the UK.
ITV News Reporter Martha Fairlie reports:
In addition, a 29,000-strong backlog of unresolved asylum applications dating back to at least 2007 means a "worrying" 11,000 asylum-seekers have been waiting for at least seven years for an initial decision on whether they can stay in the country, the report found.
As well as longstanding applications, the department is also struggling with fresh asylum claims, the PAC report said, with a backlog of cases awaiting an initial decision jumping 70% to 16,273 in the first quarter of this year.
This is partly as a result of a "botched" attempt by the now-defunct UK Border Agency to downgrade staff that resulted in 120 experienced caseworkers leaving, the PAC report added.
PAC chair Margaret Hodge said: "The pressure is on, and the Home Office must take urgent steps to sort out this immigration mess."
The Home Office scrapped the UK Border Agency in March 2013 over concerns with its performance and passed operations to UK Visas and Immigration, Immigration Enforcement and Border Force.
These three directorates collectively spend some £1.8 billion per year, the PAC report said.
In 2012, the Department reduced some 400,000 asylum and migration claims dating back to before March 2007 to 41,000 cases, but the PAC report said this still stands at 29,000 with a "worrying" 11,000 backlog cases where no initial decision had been reached.
Yvette Cooper, shadow home secretary, said: "Theresa May was very quick to blame the UKBA, but since she took direct control of the border force and immigration system, we have seen backlogs increase sharply and the admission that the Home Office have no idea how many of the 175,000 failed asylum seekers are still here or where 50,000 failed asylum seekers even are.
"However, the failures don't stop there. David Cameron and Theresa May have failed to deliver on her promise to introduce exit checks, to reduce net migration to the tens of thousands, has cost the taxpayer £1 billion on failed IT projects and as the report says introduced no processes to rectify these and other failings."
Immigration and Security Minister James Brokenshire said: "The immigration system we inherited was totally dysfunctional with systematic abuse of family, work and student visas and an agency overseeing it all that was completely incapable of the task.
"UKBA was a failing organisation that could not deliver an efficient immigration system for Britain. This is why we split it up into three separate divisions to improve focus on their specific roles in delivering a controlled immigration system and bring them under the direct supervision of ministers.
"Turning around years of mismanagement has taken time, but it is now well under way. We have reformed visa routes to make them more resistant to fraud and cancelled failing contracts; and we are addressing the backlogs we inherited."
The Home Office said it was on track to make a decision on all of the 11,000 asylum applications by the end of this year.