Postal services could be hit by prolonged strike action over plans to process North Yorkshire's mail in Leeds at weekends.

Royal Mail says it wants to take all the 90,000 items collected within the York postcode area each weekend over to Leeds.

There, about 30,000 letters being sent to York postcode addresses would be separated from the rest and transferred back to York for sorting, while the remaining 60,000 would be sorted in Leeds.

Unions claimed today that the proposals threatened both the quality of service to customers and also workers' ability to earn vital overtime and bonuses.

The Communications Workers' Union said it also feared the changes could be a forerunner to the eventual closure of York's sorting offices, with the loss of hundreds of jobs.

Branch secretary Paul Clays warned that unless the plans were withdrawn, a ballot would be held on whether to take prolonged industrial action.

But Royal Mail insisted that the changes, due to be introduced in August, would have no impact on the level of service to customers and the York sorting office would not be closing down.

A spokesman said only six per cent of the mail posted each week in the York postcode area was collected at the weekend, and there would be no impact on jobs at the York office.

But Mr Clays claimed the proposals would throw up a range of problems threatening the high quality of service currently provided by the York office.

He said separating the mail in Leeds between letters bound for York postcode addresses and those sent elsewhere, would prove difficult, particularly when people had not written on the postcode.

He claimed postal workers were so badly paid that they relied on overtime for working at weekends, and on bonuses paid for the high quality of service provided by York, to pay their mortgages and clothe their children. "They do not come in at a weekend for the fun of it."

York MP Hugh Bayley said: "I am very concerned about the changes and have written to the area manager to ask what is happening," he said.

Updated: 10:40 Thursday, June 14, 2001