A private company paid hundreds of millions to look after Islington’s valuable properties are leaving them to rot, a housing expert claims.

Partners for Improvement in Islington (PfI) get almost £40million a year from the council for improvements and general upkeep of 6,500 council-owned properties in the borough – many of which are listed or are in conservation areas.

As part of the work, each dwelling was brought up to the “decent homes standard” at a cost of £32,000 each – including refurbishing the exterior of the properties to protect the homes for seven years.

But Thomas Cooper, vice chairman of the PfI residents’ forum, says the work is shoddy and is causing lasting damage to the properties.

He said: “This is damming proof that Islington Council is dealing with a contractor who simply does not care about delivering reasonable quality works, yet gets paid £39.4m a year for delivering a poor standard of work.”

“This work is clearly defective – they have slapped paint over existing disrepair and now this has been shown up.’’

Mr Cooper said the windows in one resident’s home, in Ronalds Road, Highbury, were so bad she has to nail her windows shut to stop them from flying open.

He said: “Now that Catherine West has quit as council leader, if the new leader finds there is flaking paint, rotten metal, rot and fungus, then they might think about whether or not Islington Council should terminate the contract. The works are a sham.”

PfI borrowed £240m to refurbish the properties under the decent homes programme, but will be repaid about £800m by the council by the time the contract ends.

A spokesman for PfI said their work was inspected by independent surveyors and the long-term contracts were awarded to them after a competitive tendering process on the open market.

He added: “We would like to apologise to any residents who feel that their external painting has not lasted.

“We have directed our contractor to inspect the properties with us and will ensure that any problems identified are put right at no cost to the residents or the council.

“We want to work in partnership with the council and engage with local residents in a positive way as we have been doing for the last 10 years.”