Nearly 240 council homes in Hounslow are lying empty, costing taxpayers up to £1.5 million a year in lost rent, it has been revealed.

The huge number of so-called 'void' properties in the borough has been blamed on the repairs backlog at Hounslow Homes, the council's housing arm.

In the last three months of 2014, the average time taken to fix up a property and get it re-occupied has shot up from 41.6 days to 52.3 days, according to a report produced for the council's overview and scrutiny committee.

The council last month brought in an asset management company, which has a turnaround time of just eight days for its properties, to help Hounslow Homes address the delays.

Conservative councillor John Todd, who exposed the figures, criticised the 'wholly inadequate performance' at a time when there is a huge demand for social housing, though he acknowledged action was now being taken.

"The evidence uncovered so far indicates poor and wholly inadequate performance in both Hounslow Homes and Hounslow Council, resulting in a loss of income and the ineffective and inefficient use of our much needed social housing  estate," he said.

"I have two tenants living in damp and unacceptable accommodation - victims of Hounslow Homes' vacillation and obfuscation. The initial potential performance data from the private sector and our voids/repairs data highlights indifferent and wasteful practice, poor performance requirements and a need for a more vigorous approach in governance terms."

A report presented to the scrutiny committee on Wednesday (February 5) showed there are currently 236 council properties across the borough which have lain empty for between three weeks and over 14 years.

That represents more than two per cent of the total stock managed by Hounslow Homes and equates to £1.46m in lost rent over the course of a year.

Many of these properties are being deliberately left empty so the council can demolish the building for redevelopment or undertake major renovation work, the report suggests, but many are lying unused because of the delay in carrying out repairs.

They include a six-bed house, in need of major renovation, which has been sitting vacant for more than two years.

Pyramid Plus London, which is jointly run by A2Dominion and Breyer Group, has been working with Hounslow Homes since January 6 to speed up repairs.

Councillor Steve Curran, the council's cabinet member for housing, planning and regeneration, said: "I agree that a number of our empty council homes, known as voids, have remained vacant for far too long. I'm grateful for the cross party support of the scrutiny panel when we looked at the issue.

"We are working closely with Hounslow Homes to renovate properties that come back to the Council as fast as possible. When we are able to reduce the turnaround time between lets, we will lose less rental income. To help achieve this, we have appointed Pyramid Plus London, who are market leaders in council home repair times, to improve our systems and processes and reduce void times.

"It is worth pointing out, however, that in many cases an extended period of void time is necessary as the property needs to undergo extensive repairs or needs to be redeveloped to fit a new purpose. This includes properties which had been used as sheltered accommodation being bought back into general use - over 130 out of our current 240 current voids are sheltered properties awaiting these types of works. At the moment, these properties are not fit for purpose.

"Of the remaining 100 or so properties, approximately 42 per cent are undergoing major repairs.  The remaining 60 properties are about the same as the number of new voids that we receive each month."