The strike had spread to the east coast

Deliveries in the central belt had also been facing severe disruption after the action spread to Edinburgh and Perth.

However, workers in Edinburgh also voted to end their wildcat strike on Wednesday afternoon. Their counterparts in Perth are expected to follow suit.

The workers had been protesting at what they saw as the lenient treatment of a manager over inappropriate comments to a teenage female employee.

The man was given a formal warning and moved to another department, and the Royal Mail said the matter was closed.

The decision to end the strike action in Glasgow was carried by 382 votes to 96.

It is in no way related to any issues in the Edinburgh area, which makes it all the more disappointing to our customers in the east

Steve Cameron, Royal Mail

About 3,600 postal workers walked out on Tuesday in the west of Scotland, leaving up to two million items of mail undelivered.

The strike action then spread to Edinburgh, with about 1,000 workers walking out in the capital after refusing to handle mail from Glasgow.

That move sparked a furious reaction from the Royal Mail, which said the strike had nothing to do with the east coast.

The company's area manager in the capital, Steve Cameron, said he would sympathise with customer anger over the unofficial action.

He said: "It's difficult to get a reason (for the action).

Jobs warning

"It seems to be in support of the Glasgow dispute and it is in no way related to any issues in the Edinburgh area, which makes it all the more disappointing to our customers in the east."

The company warned that the dispute could put jobs at risk.

The Communication Workers Union refused to support the action and urged the staff to return to their jobs.

Around 1,100 staff at the Glasgow Mail Centre took part in the action, along with 1,500 at 18 delivery offices in the city and 1,000 at 10 other delivery offices in the west of Scotland.

The Edinburgh Mail Centre and five sorting offices in the east were also affected.