Immigration Minister Damian Green is facing tough questions over chronic delays at Heathrow Airport's passport control that leave some passengers waiting for hours.
Long queues at the west London hub last week have led to fears over immigration officials' ability to process passengers arriving in the UK ahead of the Olympics.
Heathrow's owners admitted the situation was "unacceptable" and blamed Home Office staff for lengthy waits at peak times.
Alastair Campbell, the former Labour communications chief who was caught up in Thursday night's queues, tweeted: "If this is what Heathrow T5 border queue is like on an average Thursday, Olympic athletes should think about coming soon."
Mr Green is to be grilled by MPs about waiting times, it has emerged.
If this is what Heathrow T5 border queue is like on an average Thursday, Olympic athletes should think about coming soon. Alastair Campbell
Keith Vaz, chairman of the Home Affairs Select Committee, said: "There is a real problem and the problem has emerged over the last few months.
"I'm not saying we should abandon checks, but it's a choice for the government - you either look at the way you deal with people when they arrive at Heathrow or you recruit more staff.
"This is not just about the Olympics, this is about what happens before and after, it's about Heathrow as a world-class airport and it's about our reputation, and we need to make sure we get it sorted," Mr Vaz said.
The Labour MP said that queues of more than half an hour were not acceptable.
"I would have thought by the time you get off a plane and you've walked a long way from the plane to immigration, half an hour would be a problem," he said. "Anything from zero minutes and 30 minutes would probably be acceptable but people would expect to get through much quicker."
A spokeswoman for airport operator BAA, which owns Heathrow, said Friday night's long queues, which saw passengers waiting for up to an hour, had cleared by midnight.
Immigration waiting times during peak periods at Heathrow recently have been unacceptable and we have called on the Home Office to address the problem as a matter of urgency. BAA
On Saturday morning, she said: "Everything is looking quite good in the immigration halls. Things are moving and we haven't got major queues.
The Border Force is putting staff where they are needed at the moment."
She added: "Immigration is a matter for the Home Office. Immigration waiting times during peak periods at Heathrow recently have been unacceptable and we have called on the Home Office to address the problem as a matter of urgency.
"There isn't a trade-off between strong border security and a good passenger experience - the Home Office should be delivering both."
A Border Force spokesman said: "We will not compromise border security but we always aim to keep disruption to a minimum by using our staff flexibly to meet demand."
No date has yet been announced for Mr Green's appearance before the Home Affairs Select Committee.
22 December 2010
06 February 2012