Experts say the need for affordable housing in Sussex and the South East is 25 per cent higher than predicted a year ago.

House prices in the region have risen to almost five-and-a-half times the average income, compared with just under five last year.

The figures released by the National Housing Federation South East come on the back of a report by estate agency Fox and Sons which says that the value of some Sussex homes has risen by more than half in the past year.

Bernadette Stokoe, Head of South Regions at the National Housing Federation, said: "Local people on lower incomes are already being squeezed by high house prices on one hand and a shortage of low-cost rented housing on the other.

"People need good quality housing and if we can't provide it, our essential public services and eventually the whole South East economy will be hit as people move out to cheaper areas where they can afford somewhere reasonable to live."

The shortage of affordable housing is being exacerbated by a population increase of some 600,000 people in London and the South East, according to research carried out by Cambridge University for the NHF.

New projections from the Office of National Statistics show the population in England is almost a million higher than when it was last estimated in 1998, with the South East and London shouldering more than 60 per cent of the increase.

This has fuelled the need for over 250,000 more homes in these regions than previously estimated.

Researchers say there is little hope of London accommodating all of its extra households many of whom will move out to the South East.

Ms Stokoe said: "We need to be building around 15,000 affordable homes for rent every year between now and 2016 in the South East.

"At the moment we're only producing around 4,000 affordable homes a year and even that figure is largely offset by the loss of rented housing through the Right to Buy. We must start producing a lot more low-rent homes for local people and fast.

"We are calling on local authorities to make sure their planning policies allow for the speedy release of land earmarked for development in their local plans."