Air traffic controllers have warned that proposals to reduce delays at airports will "compromise safety".
The Civil Aviation Authority wants to impose new penalties on National Air Traffic Services for delays cased by controllers. If it misses the targets then Nats - whose shareholders include British Airways, Virgin, BMI, easyJet, BAA and the Government - could be fined up to £10m.
But Prospect, the controllers' union, believes that this will put too much pressure on Nats staff. David Luxton, national secretary of Prospect, said: "There seems to be economic regulation in isolation of everything else. Without regards to safety then this will compromise safety. The proposals will lead to more overloads and put a tremendous strain on the individual air traffic controller."
The CAA is considering setting Nats a target of no more than a 1.2 minute- average delay per flight. This compares to a 2.2 minute- delay for 2002-03, reported in Nats' annual accounts filed at Companies House on Friday. Nats' latest business plan sets a target of 1.5 minutes' delay.
The CAA is set to make its final ruling this week. A Nats spokesman said: "We would never allow safety to be compromised and neither would the regulator."
Nats' accounts show that it made a profit before tax and exceptional items of £12.7m, compared to £4.4m in the previous year. After exceptional items, Nats lost £29.1m compared to £79.9m in 2001-02.