Boris Johnson looks set to approve the heavily criticised plans for London’s largest brownfield site despite an eight-month campaign involving thousands of residents.

The Mayor of London has been at the centre of a row over the Royal Mail’s proposals for its former sorting office at Mount Pleasant in Farringdon Road since he called in the decision in January, taking it out of the hands of Islington and Camden councillors.

Despite both councils rejecting the plans – which would see 700 mostly private flats rising as high as 15 storeys – and a passionate campaign from Mount Pleasant Association (MPA), the development has been recommended for approval in a GLA report.

Residents were branded “bourgeois nimbys” by Mr Johnson in February after he was criticised for calling in the decision at a London Assembly meeting.

Edward Denison, chairman of the MPA, which offered an alternative scheme backed by architects, said: “It would seem the writing is on the wall from reading the report.

“What I find profoundly frustrating and depressing is that there’s so much doublespeak in it. Whenever they say white is white it’s actually black.

“They list the several ways in which the plans breach guidelines but then say they ‘don’t do any harm’, that’s just an opinion – we’re saying they do do harm.

“What’s the point of having planning guidelines and laws if you’re not going to stick to them?”

In the report parts of the development which breach guidelines in terms of height of the buildings are said to “provide well considered variety to the streetscape”, while the author disagrees with both councils and English Heritage in their assessment that this would cause “significant harm” to listed buildings in Calthorpe Street, downgrading the harm as “slight”.

Other allowances include applying a “greater degree of flexibility to the BRE [building regulations and dwelling emissions rate] guidelines” which set out the acceptable amount of sunlight which can be lost to neighbouring homes.

A report from charitable public policy think-tank the Legatum Institute is the latest respected body to criticise the plans.

Published last week it says: “We do not believe that the plans maximise connectivity, sustainability or long- term value for the Royal Mail Group or the taxpayer.The proposals are also very unpopular with the local community.”

The report also urged landowners and investors to “think of residents not as a nuisance to be consulted but as allies to be empowered”.

The GLA public hearing takes place at 10.30am tomorrow at City Hall.