THE number of towns in the region where key public sector workers cannot afford to buy a property has increased by more than six times in just three years, research shows today.

Nurses now find themselves priced out of 79 per cent of towns in the North, as opposed to 13 per cent in 2001.

Firefighters are priced out of the market in 85 per cent of northern towns, according to Britain's biggest mortgage lender, Halifax.

Elaine Kay, northern regional secretary for the National Union of Teachers, warned the Government to act now before it was too late.

The survey found that the problem of affordability for crucial workers such as teachers, nurses, firefighters and police officers was no longer confined to London and the South-East.

Although the North scores well in the affordability tables, a nurse in Darlington would still have to borrow 5.7 times his or her salary to pay for an average property.

And in Harrogate, the most expensive town in the region, a nurse would have to borrow almost ten times their salary to buy a property.

Peterlee was ranked as the fourth most affordable town in the whole of the UK for key public sector workers.

However, a nurse would still have to borrow 3.3 times a salary to buy an average property there.

Despite the gloomy figures, the North remained one of the most affordable places for key public sector workers to live.

But unions fear future nurses and teachers could be put off the profession because of the lack of affordability.

Ms Kay said: "There is already a shortage of teachers and they are underpaid for the professional job they do.

"The Government needs to act now to prevent the same situation happening in the North as it is in the South, and increase teachers' pay before it is too late. There is now a national crisis and the Government needs to sit up and take notice in terms of paying teachers more."

Across Britain, nurses now find themselves priced out of the market in 93 per cent of towns in Britain, while firefighters would be unable to get on the property ladder in 90 per cent.

The number of locations where teachers can't afford to buy a home has nearly doubled from 34 per cent to 77 per cent since 2001, while houses in 71 per cent of towns are now beyond the reach of police officers.

There are now only two towns in Britain where nurses could buy a home with a traditional mortgage of three times their salary - Lochgelly and Cowdenbeath, both in Scotland. They could afford property in another five locations - including Peterlee - if they borrowed three-and-a-half times their pay.

Martin Ellis, chief economist at Halifax, said: "Housing is more unaffordable for more key workers than ever before. Unaffordability was previously a London phenomenon but has now become a national issue.

"The current Government-sponsored key worker schemes are weighted heavily towards London and the South-East. There is now a strong case for the Government to significantly extend the reach of these schemes outside the South.