House prices have increased 259% since 1997 compared to a 68% increase in average earnings in the same period, making houses in England and Wales the least affordable they have ever been, the Office for National Statistics (ONS) has reported.

The average house now costs 7.6 times average annual earnings, compared to 3.6 times earnings in 1997, the ONS said. The rise in house prices has helped to reverse a century of rising home ownership and driven an increase in private renting, especially in London where house prices have risen the fastest.

Figures from the annual housing survey, published earlier this month, found that home ownership in Britain had fallen to the lowest level since 1985 last year, with 62.9% of the population owning their own home, down from a peak of 71% in 2003.

While all areas of the UK have become more unaffordable over the past two decades, the gulf between earnings and prices is widest in London and particularly in the borough of Kensington and Chelsea.