Staff at one of Sussex's biggest engineering firms could strike over a pay dispute.

Members of the Amicus trade union called a ballot after a row with employer BOC Edwards.

The firm produces high-tech vacuum pumps and employs more than 1,000 people at five sites across Sussex - Crawley, Shoreham, Burgess Hill, Eastbourne and Newhaven.

Union leaders claim workers at three of these have been treated unfairly in pay negotiations and representatives have called a postal vote over industrial action.

If members approve the strike action, a walkout would probably be in mid-July.

A spokesman for Amicus said: "The management offered a deal of a lump sum which is under half of what they announced they would give another group of workers the other side of the gangway doing a similar type of job.

"We are dissatisfied being treated so differently and feel we have to go down this route, which is most regrettable but there is no alternative.

"The result of the ballot will be on July 9 and we would have to give a week's notice for industrial action, so any strike would be the week after that."

The spokesman said about 400 manual staff at BOC Edwards' plants in Eastbourne, Shoreham and Crawley were affected by the pay dispute.

He said every union member within the plants would be sent postal ballot forms, as would members of the GMB union.

A spokesman for BOC Edwards in Crawley said today: "I can confirm the ballot is taking place. The ballot papers were received yesterday. The result will be on July 9 and we will wait and see what the result is."

In 1998, the company announced it was axing 165 jobs across Sussex and 500 in the UK. More job losses were revealed in 2001.