Competition for building land is causing some problems

Ocean Housing said 5,000 people are currently registered on its lists, but it can only build 150 new homes a year.

It said problems included shortages of building space, developers buying land and potential neighbours' "nimbyism".

Cornwall County Council said that the issue of affordable housing was a critical problem.

Space shortages

Ocean Housing said waiting lists were growing so fast only the most desperate cases can expect a property.

Managing Director Chris Blackbeard said the organisation had 200 vacancies in 2005.

"If we're only homing 200 a year, then it could take us up to 20 years to clear a list of 5,000," he added.

The association said problems included potential neighbours' objecting to social housing built close to them when plans were published.

But competition for development land is also a major issue.

Mr Blackbeard said: "We're a non-profit-making organisation, and we're competing against private developers who are looking to build home for the private sector and can afford to pay more than we can."

Cornwall County Council said providing enough affordable housing was a problem that had come about over several decades and there was no easy solution.