MAJOR property developers are “gaming” the system to build on large rural green field sites without delivering on promises of affordable homes, campaigners have warned.

Hundreds of affordable homes drawn up by developers become more expensive and profitable homes once realised in bricks and mortar, according to the Sussex branch of the Campaign to Protect Rual England.

The group believes legislation brought in by the last Conservative government is putting too much pressure on councils, desperate to meet housing targets, into accepting affordable housing provision well below their own targets.

Developers said they were delivering hundreds of affordable homes and delivering millions of pounds of infrastructure improvements to the county.

Campaigners have highlighted the £1 billion new neighbourhood at North Horsham, backed by the district council’s planning committee earlier this month, as a prime example with Liberty Property Trust allocated “a vast tract of open countryside” in the Local Plan on the basis of providing almost 1,000 affordable homes.

The final application has seen that 35 per cent of affordable housing drop to 18 per cent.

CPRE also pointed to development plans on fields in Lower Horsebridge in 2015 on the proviso that 12 affordable rural homes would be provided but the developer is now changing that proposal; first in successfully gaining permission for an extra 20 full-price homes and now applying to increase the development to 110, largely market priced, homes.

The group have also raised concerns about whether Albion will deliver 180 affordable homes as part of its £170 million development bringing Ikea to New Monks Farm near Lancing.

CPRE Sussex Bill Freeman claims there is a serious risk the level of affordable housing would be dropped in time because of high infrastructure costs.

Albion director Martin Perry said the development would deliver on its promises of 30 per cent affordable housing.

CPRE Sussex director Kia Trainor said: “Under the current system, councils are penalised if houses are not built quickly enough against unrealistic targets and this means that they are in a poor negotiating position.

“The next government needs to shift the blame elsewhere if it truly wants to see a step increase in the amount of affordable homes being built in Sussex.”

Andrew Blevins, managing director of Liberty Property Trust, said: “Our plans come with an overall infrastructure and community benefits package of around £50 million, which includes a commitment to 30 per cent (825) of the new homes being allocated specifically as housing for local needs.

“Independent experts appointed by the council determined that this was the right level for this development.

“We have also agreed a review mechanism that will establish whether this contribution can increase to the council’s target of 35 per cent as the development progresses.

“We are committed to delivering almost 500 affordable rent and shared ownership properties alongside a broader spectrum of home types.”

A Horsham District Council spokeswoman said: “Development does not happen if it is not viable and developers are required to submit detailed financial appraisals.

“Significant progress was made during the negotiations on the application and these included agreement to a review mechanism which will ensure that increases in the value of the development over time will be used to generate additional funds for affordable homes.”