A survey by the Halifax Building Society has shown that nurses, police officers and teachers in Truro have been hit harder than anywhere else by rising house prices.

Cornish MPs have written jointly to the housing minister Yvette Cooper after the Halifax released data showing Truro had seen the worst increase in housing "unaffordability" for "key workers" in the UK.

According to the research conducted by Halifax Building Society, while in 2002 home ownership in Cornwall was already impossible for some, now none of the key workers assessed can afford a home in Cornwall.

The research covers fire men and women, the police, teachers, nurses, and ambulance staff. Truro has experienced the greatest deterioration across the country, with house prices almost ten times the average key worker wage.

Cornwall's Liberal Democrat MPs are pressing ministers for a solution to the lack of affordable housing in Cornwall, where incomes remain amongst the lowest in the country.

Responding to the new figures, they have written to Housing Minister Yvette Cooper, setting out three 'key solutions': * Planning procedures to stop more family homes being bought up for holiday use * Greater funding to build more affordable housing stock * Powers over strategic housing planning to return from the region to Cornwall so that local people can determine local solutions.

The city's MP Matthew Taylor said: "The fact that the men and women providing Cornwall with essential services cannot afford to own a house here is a disgrace. Firemen and women, the police, teachers and health service staff deserve the kind of security that can only come from owning your own home, but thanks to meagre wages and Government neglect they are left out in the cold.

"Ministers need to recognise the seriousness of this situation. Eventually Cornwall's key workers are going to be driven out, and then where will we be? The Government needs to take responsibility for finding a solution to the problem of second homes, they need to provide the much needed money for housing stock, and they need to give local people the power to decide where and how it should be built."

The move comes as the campaign against second home ownership takes a sinister turn with the Cornish action group An Gof calling for second home ownership in the county to be stopped.

The group has attacked key sites in the county, including the railway bridge over Arch Hill, by spraying them with with graffitti slogans.

The move has been condemned by Mebyon Kernow - the Party for Cornwall.

"Mebyon Kernow - the Party for Cornwall unreservedly condemns the vandalism carried out by those misusing the name 'An Gof' and we call upon all other Cornish organisations to publicly disassociate themselves from the attacks.

"We believe that these mindless actions are those of one or two misguided individuals who do not realise that their negative actions are undermining the good work being done by so many people, campaigning hard for a better deal for Cornwall.

"We would appeal to whoever are calling themselves 'An Gof' to stop what they are doing and work for Cornwall through other positive means."