Prospect will now press NATS management to improve the offer, worth 6% over two years, which was rejected by a vote of more than four to one.

"This overwhelming rejection reflects discontent among controllers over a whole range of issues," said David Luxton, Prospect aviation officer.

"They feel undervalued by comparison with the pay of controllers abroad, but also because of pressures over workload, the new Swanwick centre and uncertainty over the very future of NATS."

The controllers’ branch council will decide how to proceed at a two-day meeting next week. They have put in a request for an urgent meeting with NATS management to resume negotiations on the offer.