Letters and parcel deliveries are subject to unprecedented delays as Royal Mail struggles with thousands of staff absences, demand for Covid-19 tests and a deluge of Christmas returns.
Around 15,000 - or one in seven - of the postal service’s workers were sick or isolating as the omicron variant spread in the first week of January. The figure still stood at 13,000 last week, double the normal level for this time of year.
The company is juggling millions of coronavirus test kit deliveries and huge parcel volumes, which have surged during the pandemic and currently also include a wave of Christmas gift returns.
More than 1.5m coronavirus test samples were posted for analysis by households and “satellite” centres such as care homes in the week to Jan 5, official figures show.
Royal Mail is responsible for these under a government contract worth up to £790m.
It has led to a situation where inundated sorting offices are being forced to prioritise test samples and packages at the expense of letters - partly because the mountain of parcels would otherwise take up too much space.
Households are nonetheless still waiting weeks for post that should arrive in just one or two days, from expensive tracked packages to well-overdue Christmas cards, legal documents and letters for hospital appointments.
Some neighbourhoods in Manchester say they have not received any letters for more than a fortnight.
A total of 77 areas were not receiving post regularly at one stage, although Royal Mail said the figure had since dropped to 44.
The problems are affecting places as far apart as Bicester, Islington, Redcar and Perth, with as many as one third of staff absent at some sorting offices.
A spokesman said: “We are providing targeted support to the local offices affected by these issues and we apologise to customers for any inconvenience they may have experienced.
“Our postmen and women are continuing to work incredibly hard, as they have done throughout the pandemic, and we are thankful for all of their efforts and determination.”
The company, which has 1,200 sorting offices, insisted it is operating as normal across most of the country.
In a bid to battle the backlog, it is bringing in temporary workers, offering staff more overtime and has temporarily cut the frequency of deliveries in some areas.
But it risks breaching the “universal service obligation”, a legal duty which is supposed to ensure deliveries within a certain time, after being hit with delays last year as well.
Under the obligation, Royal Mail is supposed to deliver 93pc of all first-class post within one working day of collection and 98.5pc of second-class post within three working days.
It will be measured for the financial year to the end of March, but performance is only being assessed for September, October, November, January, February and March this year owing to pandemic exemptions. December is never counted.
If the average delivery times for those six months are found to be below standard, Royal Mail could face a fine from media regulator Ofcom. It was previously fined £1.5m for missing targets in 2018/19.
A spokesman for Ofcom said officials are closely monitoring the company's performance.
He added: “We have made it clear to the company that it must improve as the impacts of the pandemic subside.”
One postal worker in the South East described the scenes playing out in sorting offices as “chaos”.
They said: “There is not enough space, so managers are saying ‘leave the letters and get rid of these parcels first’.”
The postal delays have triggered a slew of complaints to Royal Mail and its management, including chairman Keith Williams and UK chief Simon Thompson.
In one example, the leader of Buckinghamshire council said he had written to Mr Williams to complain that a resident had received 24 Christmas cards all at once on January 5.
“Infrequent and unpredictable” service had prompted long queues of residents outside the sorting office in Amersham, which only opens between 8am and 10am, hoping to personally collect essential mail, he added.
Royal Mail refused to say how big the current backlog of letters and parcels was on Tuesday.