House prices look set to rise by 10 per cent this year despite concerns that the increases are becoming unsustainable, Britain's biggest building society has revealed.

Nationwide said values had already risen by three per cent during 2002, while annual house price inflation for the year to the end of March remained steady at 13.8 per cent.

Alex Bannister, the society's group economist, said: "Although we still expect price growth to slow later this year, we are now revising our original six per cent house price inflation forecast up to 10 per cent."

Last month, the Oxford Mail revealed house prices in some areas of Oxfordshire had risen by up to 120 per cent in the last five years -- outstripping London, as people move out of the capital.

Nationwide warned that double-digit growth was ultimately unsustainable, and it expected problems with affordability to eventually slow the market.