British lawmakers are questioning Heathrow Airport's ability to cope with an influx of passengers during the London Olympics this summer.
The House of Commons Culture, Media and Sport committee is warning that long lines at immigration could force planes to sit on runways or circle the airport, Europe's busiest.
The concerns were expressed in a letter to Culture Secretary Jeremy Hunt from committee chairman John Whittingdale.
Whittingdale noted while significant preparations have been made to accommodate Olympic athletes and equipment, "far less thought" has been given toward coping with immigration lines at Heathrow.
Last year Britain's former border chief relaxed some passport checks during the busy summer tourist season just to handle the demand.
The Olympics run from July 27 to Aug. 12.