Private developers overseeing the transformation of Hoxton’s Colville Estate have stunned council bosses by objecting to the £384million Britannia Leisure Centre project next door.

Anthology paid top planning consultants at Rolfe Judd to submit a 12-page letter to the town hall in April, now made public for the first time, claiming the planned scheme breaches the town hall’s own policies.

As well as providing the Hyde Road centre with “state-of-the-art” new leisure facilities, the plans include a 900-place secondary school, 480 new homes – 80 of which will be affordable – and a new cafe and toilets accessible from Shoreditch Park.

The project was signed off in principle by the council’s top table last year and a consultation is now taking place over preliminary plans.

It has already had its fair share of controversy. A group of neighbours are fighting the plans because they don’t want the Britannia demolished or any of Shoreditch Park built on, and don’t want hundreds of unaffordable homes to spring up on their doorsteps.

That group, Save the Britannia Leisure Centre, uncovered the objection letter after a meeting with the council in which they asked to see all the objections.

In it, Anthology, which has worked closely with the council on the Colville Estate regeneration, claims the Britannia project is unviable and accused planners of “overdeveloping” to compensate.

The “overdevelopment” referred to is the two tower blocks – 16 and five storeys high – proposed at the corner of Penn Street and Bridport Place, next to the Colville Estate.

Anthology says they are “excessive” in height, bulk and density and don’t meet the affordable housing policy quota of 50 per cent.

On the housing mix, the letter states: “The viability of [the two blocks] and the negative impact this has on the overall viability of the application scheme should be critically and independently assessed.”

Anthology has accused the council of not publishing documents that validate the viability of the scheme, particularly regarding the two blocks.

The Colville Estate regeneration is bringing 880 homes, half of them affordable.

“Anthology has been working closely with the council on the regeneration of the Colville Estate,” the letter adds, “and is therefore disappointed the council has sought to bring forward this development proposal without any design or phasing consideration to the regeneration of the estate.”

What’s more, Anthology argues that placing all the affordable housing in one block, the 16-storey tower, is “illogical” and means the most expensive building of the project won’t contribute towards the wider viability of the site – in that it won’t make any profit.

The letter argues more affordable housing could have been provided had the planned affordable homes been placed elsewhere.

Campaigner Pat Turnbull welcomed the letter. She told the Gazette: “While their views are not identical with ours, as their interests are different, they coincide with ours on certain points. This is only one of 80 objections. Only eight submissions are in favour.”

A town hall spokesman said the Anthology objection was no more than one of many comments to be analysed that had been “carefully reviewed” as part of the consultation.

“Further information is being collated to address various issues raised,” he said, “and this will be submitted to the local planning authority this month and be subject to a further statutory consultation.

“The council will also be in a position to publish the full viability assessment and appendices at this time.”

Mayor Phil Glanville has also had a say, reiterating his stance on why the leisure centre development is needed.

He said: “The amount and mix of housing we’re proposing – 81 homes for social rent and shared ownership, and up to 400 for sale at market rate - is because we need the income from the homes to help fund the rest of the development.

“Building new infrastructure on this scale comes with challenges – it’s a balancing act, you can’t please everyone, compromises have to be made, people often don’t like change or new developments near them, and it’s regularly clouded by misinformation.

“Throughout this project there have been many consultations, public meetings and opportunities for people and valued partners like Anthology to share their views.

This will continue and we will continue to listen.”