The council’s planning department has been accused of being “unfit for purpose” after backing a development that breached regulations.

Hounslow Council’s Heston and Cranford area committee was due to decide last night whether to allow the owner of a property in Sutton Road to keep five flats – though the authority had previously only granted permission for four.

Officers proposed last night that councillors approve the retention of the two-storey building, which has three two-bedroom and two one-bedroom self-contained flats in the roof space, with parking and landscaping.

Nick Marbrow, of Heston Residents’ Association, said the development had been in “significant and substantial” breach of planning regulations for nearly four years, and criticised the officers’ proposal for retrospective approval.

He said: “The planning department appears to be arguing against its original report for administrative convenience.”

Mr Marbrow expressed concern that if the committee supported the proposal it would give developers the green light to ignore planning regulations in future.

Residents have complained about the 1,100-litre rubbish bins in the front forecourt of the building, which are sometimes left half-open, and said they also take up spaces for cars – leaving just two for five flats.

The planning officers’ new proposal included a landscaping scheme and a refuse and recycling storage area.

Their report said: “The council does not endorse building without planning permission, but the fact the top floor flat was built without consent is not a reason to refuse the current application.

“Officers have considered the case before them on its planning merit, and have reached the conclusion to recommend that members approve it.”

The document also denied Mr Marbrow’s claim that the planning department was only proposing the approval of the five-flat development because it was “easier” than taking enforcement action.

The report said: “The planning enforcement team regularly takes action against unauthorised developments considered to be harmful.

“It appeared to officers that this development might be acceptable if mitigated by planning conditions.

“It was proper that a planning application for its retention should have been invited, in order to assess this possibility properly.”