Royal Mail is shedding roughly 400 postmen and women every week, according to the Communication Workers Union (CWU), which says the exodus has accelerated since the company rolled out its new delivery system, DM26, earlier this year.
Before DM26 arrived, the CWU says, the firm was losing about 330 postal staff a week out of a workforce of 83,000. The new system reorganised routes in the name of improved delivery performance - a phrase that has apparently not been workshopped with anyone who actually walks the routes.
The union claims DM26 is not working in hundreds of offices, and BBC Your Voice has heard from staff warning of a "nightmare" Christmas ahead as parcel volumes rise. Royal Mail, for its part, says the reforms are part of its plan to deliver a more "efficient and financially sustainable" service - two adjectives that have never once been applied to a Christmas parcel arriving on time.
Over the past year, the BBC has been in touch with more than 30 postal staff across all four nations of the UK as they switched over to DM26. The system allows second class post to be delivered only every other weekday, while supposedly guaranteeing first class mail and parcels go out every day - by putting workers into groups of three and changing the walking pattern of rounds.
But posties speaking anonymously say parcels are still being prioritised, letters left behind, and time wasted sorting and dividing mail into first and second class. "I didn't take any first class mail out on my last shift because I was on a road that's been behind for weeks," a worker in the West Midlands said. "But I'm sure a manager would have ticked a box to say all first class mail went out." A Royal Mail spokesperson said the company always worked to ensure all mail - letters and parcels alike - was delivered on time.
Only three-quarters of first class mail is being delivered on time, and Royal Mail letters have been sitting undelivered "for weeks" as parcels are prioritised, staff say.
Some postal workers say the new model is also increasing their workload. Eight workers in different areas were asked to track their average step counts. Since the switchover, all their steps increased by a quarter or even a third - often up to around 25,000 steps a day. Several fear this Christmas will be a "nightmare." "We all think this Christmas will be the worst ever, for us and our customers," said one postman in the East Midlands.
Bryn Dymott delivered post in the village of Wootton in Bedfordshire for nine years. For the most part, he loved the job. But he left the company in July, saying he couldn't face another "shambolic" Christmas. "People put things in the post for them to be delivered, not for them to be delayed because Royal Mail hasn't got the systems in place and enough people to get them delivered." Bryn says he wanted to speak out after leaving because he was sick of the fact that posties aren't able to say what's really happening. He says the company is "proving it's impossible to have four people's work done by three people. It shouldn't really come as a surprise."
So far DM26 has been introduced in about 1,000 of Royal Mail's 1,200 delivery offices. The CWU has now told its members to pause further roll-out until a plan can be agreed with Royal Mail to address the problems. The union says that while the system is operating successfully in around 500 offices, it has run into significant problems in hundreds of others. "Put simply, if a boat is already taking on water, adding more passengers is unlikely to solve the problem," said Martin Walsh of the CWU.
The union said most Royal Mail workers leaving the company were believed to be new starters on part-time contracts, but also noted an increase in staff on legacy contracts departing.
Royal Mail, meanwhile, says the new system is on track to be up and running in all offices by Christmas. It says the roll-out is 90% complete and that it is now delivering to "95% of addresses every day across the UK, up from 88% before the roll-out. The roll-out continues across our network and we expect quality of service to improve as deployment progresses." The company says it is hiring, as usual, an additional 22,000 temporary workers over the Christmas period.
Royal Mail has battled increased competition and falling demand for letter deliveries in recent years, and last week announced plans to cut 2,500 head office and other supporting roles by the end of 2027. It has also faced years of criticism from politicians and the public over slow letter deliveries - something that has continued since the new system arrived. The regulator Ofcom has fined Royal Mail more than £37m in the last three years for missing delivery targets.
But some MPs think it's time for a new approach, and a group of them will meet the regulator later on Wednesday. "We need to think outside the box," said Dave Robertson, Labour MP for Lichfield, Burntwood and the Villages in Staffordshire. "We need to bring as many people to the table on this to make sure we come up with a long-term solution because what's been tried up to now clearly isn't working."
An Ofcom spokesperson said that not only has it issued fines to Royal Mail in recent years, it has also demanded an improvement plan and reformed the obligations imposed on the company, adding: "We will continue to hold it to account using the full extent of the powers available to us." Postal Services Minister Kate Dearden said Royal Mail's improvement plan was "a step in the right direction, but it must deliver tangible improvements for customers. We will continue to hold them to account on their performance."