Flats owners in five run-down tower blocks are facing a bombshell bill of up to £40,000 each towards the “essential” refurbishment of the buildings.

The total cost of the work at Margate’s Invicta House and Ramsgate’s Harbour Towers, Kennedy House, Staner Court and Trove Court has doubled to £40 million.

Most of the 403 flats are social housing - but 32 are owned outright by leaseholders, who are being asked to stump up huge sums.

Thanet District Council (TDC) says each leaseholder will be charged between £25,000 and £40,000 towards its Tower Block Refurbishment and Retrofit Programme.

The project aims to improve energy efficiency and building safety across the blocks, with some of the work in response to new requirements following the Grenfell Tower disaster in 2017.

When councillors approved the scheme last year, it was estimated to cost £19.9 million. But recent council papers reveal this cost is now estimated at £40.34 million - a rise of 102%.

While most of these costs will be covered by council funds and government grants, the leaseholders face paying thousands of pounds out of their own pocket.

At a meeting of the authority’s overview and scrutiny committee on July 16, an officer explained to councillors: “Some of the works we are carrying out are essential for health and safety, for example, the replacement of the external wall insulation.

“Most of the increased costs are due to the external wall system remediation as we have chosen a more expensive system for its improved fire rating and reduced ongoing maintenance requirements and greater durability.

“These works are non-negotiable, and we would not gain approval from the building safety regulator for the project without addressing these issues.”

Inflation is also cited in council documents as driving up costs.

Regarding the shock bill the 32 flat owners will face, TDC’s housing officer told the meeting: “The cost may be a challenge for some leaseholders.

“We do invoice in one go, but we will be in a position to speak to leaseholders on an individual basis if this is not affordable for them, to work out an affordable payment plan over a number of years.”

The final price demanded of leaseholders will depend on the size of their flat and the number of properties in the block in question.

When KentOnline visited the tower blocks last week, residents agreed the buildings are in dire need of upgrades.

Our first stop was Invicta House. Tall and perfectly rectangular, it would look reminiscent of Soviet architecture were it not for the beige and light red colour scheme.

Its look, however, is set to change as part of the pricey works. It will instead be a muted white and grey.

Every floor has a different smell, ranging from an ambiguous staleness to decades of cigarette smoke.

A resident of 36 years, Michael Moynihan, says he is not convinced by anything the council says about the block.

“The council has done nothing with this place. They promise you new lifts, new doors, this and that,” the 67-year-old said.

“But the main issue is the bedbug situation in the block - the whole block is full of them.

“I've thrown my clothes out. I’ve thrown my laundry out.”

True to form, a mattress wrapped in plastic sits propped in the entryway to the former truck driver’s flat.

“Don’t mind about the windows and all of that, it’s the bedbug infestation,” he continued.

On the pricey refurbishments, he added: “That money should be spent on getting the infestation out and reimbursing us.”

The council tenant says he was once given the chance to buy his flat but refused.

“I was offered it years ago, but I was told by a pensioner down at Trove Court or somewhere she had to buy it and then she had to pay for this and that,” he said.

“I wouldn’t even want to own a place in here...”

Mr Moynihan’s long-time friend Hugh McGuinness believes the council should “start with the interior, never mind the exterior”.

A council tenant himself on nearby Dane Valley Road - but not in a tower block - Mr McGuinness said: “If this was a new-build it would be spotless, wouldn’t it?”

Ramsgate’s tower blocks, a few miles down the road, have their own problems.

One mum in Staner Court previously told KentOnline she felt like she and her young son were “living in a social experiment” due to the violence, noise and antisocial behaviour there.

Grace Palmer said the fire alarm had gone off five times in just a few months - and they were also being disturbed by people fighting and dogs barking.

Closer to the coast are the town’s Kennedy House and Trove Court, which sit right next to each other and look like they would fit in just as well in Krasnoyarsk (in deepest Siberian Russia) as Kent.

The interior stairwell of both is just as grey as the exterior, in the trademark concrete of the post-war housebuilding boom - both distinctive and completely anonymous.

The elevators in Kennedy House bore the aftertaste of years of stale smoke.

As council housing, almost every door in each of the blocks is identical, though sometimes with different colours.

When asked, almost every resident was shocked to hear there were any leaseholders in the towers.

One even described Kennedy House as “a very anti-social block” and said: “I wouldn’t even want to own a place in here.”

Knocking on doors in these blocks in the middle of a weekday resulted in few answers, except from what sounded like a few chihuahuas and one very large dog.

Despite endeavouring to track down leaseholders, KentOnline was unable to speak to any for this article.

But several tenants’ jaws dropped when told of the hefty fee awaiting those who own their own flats.

A TDC spokesman said: “When a person buys a leasehold property they sign a lease.

“The lease tells them what they need to contribute financially towards the upkeep of their property and block.

“This includes contributions towards cyclical works or repairs, which can be either planned or responsive.

“As a council, we have a legal duty to charge a leaseholder for their apportionment of works to the block in which they own a lease.

“If we do not charge, the cost of the works would otherwise be funded by tenants’ rents.

“This money is needed to ensure the service can continue to run.

“The leaseholders will also benefit from the works carried out.

“Their properties will be more comfortable through the energy efficiency measures and energy consumption will reduce.

“The remediation of the external wall insulation will make the sale of the properties much easier in future. They will also be more visually appealing which may increase their value.”

Of the £40 million bill for the project, about £11.7 million will come from TDC’s Housing Revenue Account budget (including the leaseholder’s payments). The government is contributing £24.3 million from its Building Safety Fund and another £4.25 million from the Social Housing Decarbonisation Fund.

Furthermore, Homes England - another government body - will reimburse TDC for the cost of the external wall insulation works, the final sum of which is not yet confirmed.

TDC’s cabinet will make the final decision on the project tomorrow (Thursday).

A spokesperson added that no official complaints about bedbugs had been received by the council.

Thanet’s most well-known tower block of all is Arlington House in Margate - but none of the flats there are council-owned.