Britain's competition watchdog criticized the level of service at Heathrow and Gatwick airports Wednesday and recommended a cap on the amount airports operator BAA can charge airlines.
The Competition Commission said lines at both airports caused "unacceptable delays to passengers, crew and flights" and that BAA, owned by Spain's Grupo Ferrovial, had "acted against the public interest."
The regulator recommended that the maximum amount BAA can charge airlines per departing passenger at Heathrow rise to 10.96 pounds ($22.36; 15.79 euros) in 2008-09, with charges rising by no more than retail price inflation plus 7.5% each year.
For Gatwick, it recommends a price cap of 5.48 pounds ($11.18; 7.89 euros) in 2008-09, with charges increasing annually by no more than inflation minus 0.5%.
The findings, which followed a six-month investigation, are separate to an ongoing investigation by the commission into BAA's dominance in airport ownership.
The government ordered that probe in March after scores of complaints from airlines and consumers and calls from airlines for the group to be broken up.
The commission has the power to order BAA to sell off one or more of the seven airports it operates around Britain, including Edinburgh and Glasgow in Scotland.