Royal Mail’s postal coronavirus "blackspots" are affecting dozens more areas than has been admitted, research by The Telegraph has found, as MPs warned that lives are being "put at risk" by the problems.

On Monday, Royal Mail published a list of 28 areas seeing "limited deliveries due to resourcing issues", but investigations reveal at least another 30 places in which services have also been severely disrupted.

In south London, Helen Hayes, the MP for Dulwich and West Norwood, expressed bemusement that parts of her constituency were not on the Royal Mail "blacklist" and said she feared problems across vast areas of the country were not being admitted.

On Tuesday, she asked the company: "Why won’t you include us on your list of areas where you admit you are failing?"

Speaking to The Telegraph, Ms Hayes said: "I’ve been in contact with Royal Mail for many months about this, but they have never acknowledged the extent of the problems or the seriousness of this impact. This is hundreds of people on many different streets and many different delivery rounds, and they’re all saying that the service has become unreliable."

David Lammy, the MP for Tottenham, said the situation needed to be resolved as soon as possible.

"Poor service from Royal Mail," he tweeted. "Because of staff shortages, constituents are waiting weeks for post, including vaccination invitations. This is putting lives at risk in the N4/N8 area. It needs to be sorted out ASAP."

Royal Mail’s list of areas with ‘limited deliveries’

The list of 28 severely affected areas, published on Monday, included 13 in or near London, as well as Leeds in West Yorkshire, Chelmsford in Essex, Widnes in Cheshire and Margate in Kent. But local leaders in other parts of the country have told The Telegraph their areas are suffering just as much.

Neil Baker, a Conservative councillor in Canterbury, said: "I’m very surprised that Canterbury is not on this list. In my area, we have had three deliveries since the first week of December. While Christmas cards could have brightened up a dark time for people, it is turning into something more serious with questions over hospital appointments and vaccine invitations."

In Stevenage, Sharon Taylor OBE, the leader of the borough council, said: "There is no doubt that there are areas of Stevenage that have been severely affected by this. I know people who haven’t had post since Christmas, and if it does come they get days and days bundled together. 

"What people are really worried about is letters about vaccinations. Older residents are really concerned that they will miss these letters."

Complaints were also made about deliveries in Colchester, Chelmsford, Bromley, Sheffield, Farnham, Basildon, Southampton, Chichester, Fife, Hastings and at least eight more London boroughs.

In an attempt to quell fears, The Telegraph has been told by well placed sources that Royal Mail staff have been instructed to look out for the vaccine invitations, which are identified by an NHS logo, so they can be prioritised during the sorting process.

A sign at the sorting office in Ashford, Kent, details temporary opening hours as the Covid crisis affects the Royal Mail workforce

Credit: Gareth Fuller/PA

On Tuesday night, a Royal Mail spokesman said: "Across the UK, our people are working hard to deliver as comprehensive a service as possible to all our customers in challenging circumstances. 

"Despite our best endeavours, it is possible that some areas of the country may experience a reduction in service levels due to higher volumes of mail during the lockdown, the ongoing impact of Covid-related staff absences and necessary social distancing measures at local mail centres and delivery offices.

"Like most organisations, we have a number of employees who are self-isolating in line with Government guidance. This has a direct impact on our staffing levels, especially in areas where there are higher levels of local outbreaks. We are working hard to deliver as normal a service as we can, drawing in extra resource and offering additional overtime where possible."