Parts of Sussex could become “retirement communities” within a generation.

Experts have warned a number of districts in the county could have three retired people for every four in work in two decades time.

They add the significant increase in the number of those aged 65 and over will place a growing financial burden on councils trying to pay for care of the elderly.

The forecast states Arun, which contains Littlehampton and Bognor, and Rother, which contains Bexhill and Rye, will be two of the oldest districts in the country by 2030.

They will also have just two people aged under 16 for every person aged over 85.

The research, by the annuity providers Partnership, is based on population data compiled by the Office for National Statistics.

Chris Horlick, the managing director of Partnership, said the two districts would become “virtual retirement communities”.

He added: "An ageing population will mean more people will need long-term care. And as medical technology improves, people will live even longer in care, which will present a real challenge for these local authorities.

“Younger people in particular face an enormous burden to meet the costs of those who are in retirement.

“It means that direct taxation and local council taxes will have to rise, or services to the elderly will have to be cut."