The Government has ridden roughshod over critics of its house building targets and told Sussex to make room for 116,000 more homes.

Publishing the final South East Plan, the product of six years of political wrangling, ministers said they wanted the county to build an average of 5,800 new homes a year between 2006 and 2026.

The move flies in the face of local authorities who have repeatedly claimed there is not enough space or infrastructure to support the “unsustainable” development.

The figure is lower than the 117,000 homes it proposed last summer, due to a reduction in Brighton and Hove’s annual average from 620 to 570 following a public consultation.

But every other part of the county has been told by the Government its targets remain the same, sidelining objections raised by Conservative MPs and the Tory-dominated South East England Regional Assembly, Nigel Waterson, Tory MP for Eastbourne, said: “Clearly the Government have completely ignored almost all representations made to them about the existing pressures on transport and other facilities in our area.

“My advice to local councils is to go as slowly as possible on any substantial new building plans because a new Conservative government would scrap these top-down targets and leave these matters to local communities to decide.”

Nick Herbert, Conservative MP for Arundel and South Downs, said: “The Government continues to ignore the concerns of local authorities that housebuilding on this scale is unsustainable and there is inadequate infrastructure, like roads and schools, to support it.

“We have said this whole process needs to be scrapped and [under a Tory government] we will no longer have these top down central targets that don’t deliver.”

Mid Sussex District Council head of planning Claire Tester said: “Over 50% of the land in Mid Sussex is an area of outstanding natural beauty and a hug part of that within the national park, so work we will be really constrained on where the houses can go.”

Other councils have dismissed the plan as “not feasible”.

Neil Parkin, leader of Adur District Council, said: “They have said 10,000 homes will have to go at Shoreham Harbour, but the feasibility study conducted on Shoreham Harbour has said it is only possible to build a maximum of 8,500, 10,000 just isn’t feasible.

“My reaction is that I’m not worried because it is a nonsense. They could tell Adur to build 20,000 houses and it is not going to happen because next year Gordon Brown will be gone and South East Plan with him.”

By contrast, campaigners for affordable homes - including Crawley MP Laura Moffatt - argued that building significant numbers of new houses and flats was essential to help families off housing waiting lists and to help young families on to the housing ladder. Under the South East Plan, 35% of all new homes would be classed as affordable.

Ms Moffatt, a Labour MP, said: “So many people come to my advice surgeries desperate for housing, which is not something we can ignore. We have to think about communities and making them decent places to live but we have also got to tackle the issue of building more housing in the south east.”

Under the Plan, the south east region as a whole will provide 654,160 over the two decades - slightly fewer than the 662,500 the Government pushed for last summer under its “proposed changes”, which were subject to further consultation last autumn.

The publication of the South East Plan yesterday, also known as the region’s spatial strategy, brings to a close a marathon period of consultation, negotiation and argument about the amount of development required in the region.

Preparation of the draft Plan, with research, workshops, opinion polling and policy drafting, began as far back as 2003, and there have since been four separate consultations on various drafts and changes.

South East Regional Minister Jonathan Shaw said: “We know that the population in the South East is aging with more people living alone and new households are growing faster than new homes. If we don't build more houses in the long term older people will have fewer choices, and the housing ladder will get even further out of reach leaving the next generation with nowhere to live.

“The South East Plan sets out an achievable vision for improving economic growth and addressing housing shortages while protecting the region’s distinctive character and environment.”

Brighton and Hove City Council were unavailable to comment.

How the figures add up:

Brighton and Hove 11,400

Eastbourne 4,800

Hastings 4,200

Lewes 4,400

Rother 5,600

Wealden 11,000

Adur 2,100

Shoreham Harbour* 10,000

Arun 11,300

Chichester 9,600

Crawley 7,500

Horsham 13,000

Mid Sussex 17,100

Worthing 4,000

Sussex Total 116,000

* The number of homes proposed for Shoreham Harbour, a strategic development area where “specific development opportunities” have been identified, “may be revised” at a later date, the Plan says.