The National Air Traffic Services (Nats) had offered its staff 6% over two years.

But the deal was rejected on Friday by 1172 votes to 274, with a turnout of 72% by the union Prospect.

Union representatives are due to hold further talks this week with Nats before a meeting on Tuesday to discuss the next move.

There are concerns about the problems within the service. Workers feel they are overworked, under growing pressures

David Luxton, Prospects national secretary

Union national secretary David Luxton said the strength of the vote showed growing dissatisfaction within the industry.

He said: "The pay rates of air traffic controllers in Britain are not relative to the rest of Europe and there need to be improvements.

"There are concerns about the problems within the service. Workers feel they are overworked, under growing pressures and there has been well-documented problems with the Swanwick computer."

Nats described the offer as generous, considering the financial difficulties the part privatised company is facing.

Nats controllers are amongst the best in the world and we recognise they perform a difficult and complex job

Nats spokesman

A Nats spokesman said members had "overwhelmingly" voted in favour of the pay offer.

He added: "Nats controllers are amongst the best in the world and we recognise they perform a difficult and complex job."

Nats was "heartened" to learn that no industrial action was being planned by the controllers' union Prospects.

"All of our discussions with the unions so far have been constructive and we look forward to continuing this dialogue in a similar manner to resolve the situation," he added.

In March, the government provided �30m in emergency funding, as part of a �60m bailout.

And airport operator BAA are said to be considering an investment in Nats of up to �65m.

The Swanwick centre cost �623m

Workers have put in complaints about the workloads at the new main control centre in Swanwick, Hampshire.

Nats said this week there had been 30 formal "overload" reports so far this year, compared to 12 in the first five months of last year.

But it denied safety was being eroded, saying there had been fewer actual incidents of near-misses since Swanwick opened in January.