Postal workers are to stage their third strike in recent weeks today, with union bosses warning that the industrial action is likely to have a major impact on services.
Communications Workers union (CWU) general secretary Billy Hayes claimed the organisation's members were being forced to strike because Royal Mail had so far failed to take their complaints "seriously".
"This is not something we want to do," he told BBC Radio Five Live's Wake Up To Money programme.
"We'd sooner be sitting down and negotiating seriously with the company," he added.
Today's strike action, which is due to begin at 19:00 BST, centres on a dispute between Royal Mail and the CWU over pay and conditions.
Postal workers have rejected a 2.5 per cent pay offer from Royal Mail bosses and insist that their modernisation plans will lead to the loss of 40,000 jobs.
However Royal Mail has stressed that the changes are necessary if the business is to survive amid tough competition from a growing number of new entrants to the UK postal market.
The situation was exacerbated yesterday, when the CWU reacted angrily after a newspaper claimed to have uncovered plans by Royal Mail to close its final salary pension scheme to new employees and make other changes to the retirement package offered to its workers.
Union bosses said the Daily Mirror report would "galvanise" support for today's strike action, but Royal Mail dismissed the "misleading allegations" and insisted that the leaked document containing the plans had already been scrapped by the company.
Nonetheless today's industrial action looks set to go ahead, with the strike due to see each section of the company's workforce walk out in two separate 24-hour protests over the next two weeks.
A Royal Mail spokesman told BBC Radio Scotland this morning that the company were focussed on "business as usual" and were confident that the latest round of strikes would not cause as much disruption as a full national walkout.
However consumer group Postwatch has warned that ongoing strike action could result in a "loss of confidence" in Britain's postal service.
Postwatch chair Millie Banerjee told the Today programme: "We think this is going to be very disruptive because if you're posting a letter from A to B and all these rolling strikes are going on you just have no idea where it gets held up."