The head of British Airways' parent company has accused the British government of misleading the public over immigration queues at Heathrow Airport.
International Airlines Group CEO Willie Walsh said some passengers were forced to wait for two and a half hours for passport checks on Friday.
He dismissed the government's estimate of one and a half hours.
The problems were particularly bad at Heathrow's flagship Terminal 5, the home of British Airways.
The queues at Heathrow, the main gateway for the Olympics and the world's biggest international passenger airport, are proving a major embarrassment for the British government weeks before the Games open on July 27.
"We have accurate, detailed information that shows that people queued for up to two hours and 31 minutes on Friday night,'' Walsh told BBC radio today. CCTV footage from the airport served as evidence of the "massive problem", he added.
But Britain's immigration minister Damian Green stood by the estimate of queueing times provided by government agency the Border Force, saying: "The figures are as accurate as can be."
Green said he could see "why people are annoyed" but said the government was working to improve the situation, including by building a central control room for the Border Force at Heathrow. The minister added that he believed Heathrow's owner BAA was in talks with airlines for carriers to fund an increase in Border Force staff.
Frustrated passengers resorted to slow hand-clapping and jeering in queues at Heathrow last week, while one fed-up traveller marched through the gates without showing his passport, media reports said.
The UK government was forced to give an emergency statement on the issue in parliament yesterday.
The IAG chief said his company had offered in the past to pay for a boost in Border Force staff, but the plan had been rejected by the government.
"We have demonstrated that we are prepared to pay when we get the right service," Willie Walsh said. "We are not prepared to pay a government that will waste money and that will not address the problem," he added.
