Key workers are being priced out of the housing market in many areas

Nurses are worst off, being priced out of the market in 93% of UK towns, said the Halifax.

Gerrards Cross, Buckinghamshire, is the most unaffordable town, with the price of the average house now 26 times higher than the average nurse's salary.

The study also said problems were no longer confined to the South East.

The number of towns in the north where property is too expensive for nurses rose from 13% in 2001 to 79% in 2004, it suggested.

Two affordable towns

Firefighters struggle to buy in 85% of towns in the region, and in 90% of UK towns as a whole, according to the research.

For teachers, the number of unaffordable places nearly doubled from 34% to 77% since 2001.

Homes in nearly three quarters of towns are now beyond the salary of police officers.

In Scotland nurses could not get on the property ladder in 62% of towns at the end of last year, compared with just 5% three years ago.

Unaffordability was previously a London phenomenon but has now become a national issue Martin Ellis, Halifax

Weybridge, Surrey, was found to be the second most unaffordable place, with property selling for an average of 20.4 times a nurse's salary, followed by Richmond, also in Surrey.

There are only two towns in Britain where nurses could buy a home with a mortgage of three times their salary - Lochgelly and Cowdenbeath, both in Fife, Scotland.

Clare Cannings, of the Royal College of Nursing, said the NHS was already struggling to recruit and retain nurses.

"Nurses will continue to leave the profession as prices put home ownership out of reach for the majority," she said.

The affordability of property in London and the South East has stabilised during the past three years as price growth has slowed down.

Martin Ellis, chief economist at Halifax, Martin Ellis, said: "Unaffordability was previously a London phenomenon but has now become a national issue."

He said government-sponsored key worker schemes are weighted heavily towards London and the South East and should be extended to other areas.