The costs of buying a home and meeting mortgage repayments are among the highest for more than 20 years, a study has shown.

Rising prices over the past decade mean that accessibility to the housing market is now almost 300 per cent worse than in 1996 and is back at the weak levels seen in 1980, the Royal Institution of Chartered Surveyors has said.

Its new accessibility index, published for the first time yesterday found that a first-time-buyer couple must save 74 per cent of take-home pay to meet the £29,200 needed for the upfront costs on a typical home, including the deposit and stamp duty.

In contrast, a couple would have needed 25.2 per cent of their take-home pay to afford their first home in 1996.

But the figure is down from a high of 88.4 per cent required in the third quarter of 2004 after lenders raised loan-to-value ratios to help reduce the value of the deposit required in relation to the value of the property.

Homeowners are also increasingly struggling with mortgage repayments, with affordability at its lowest level since 1992.

A two-person household on average incomes of £19,635 now spend 22 per cent of their income on repaying their home loan on an average house price of £147,868, up from 14.1 per cent in 1996.

RICS also predicts that accessibility will get worse with house prices likely to rise by ten per cent over the next two years.

It expects the current momentum of the housing market to continue into the second half, with property prices set to rise by seven per cent on last year's level by the end of 2006.

But RICS says the effect of rate rises will hit the market in 2007, with prices likely to rise by just three per cent.

RICS economist David Stubbs, said: "Unless house building levels improve, and levels keep pace with population growth and rising income and wealth, people will continue to find it difficult to access the housing market.

"If the housing market is to become more accessible, lenders must continue to offer generous funding levels, and the Government should, out of necessity, promote a significant increase in the housing stock.

"The financial pressures of up-front buying costs and rising energy prices will continue to create a 'have and have not' property society."

Shadow local government secretary Caroline Spelman said: "This survey shows it is so difficult to get on the ladder many young people are only able to do so with mum and dad. But the reality is a lot don't have the luxury of parents who can dip into their savings and find a deposit.

"Under Labour, home ownership is becoming the privilege of the few, and the barrage of increased taxes such as stamp duty, council tax and the abolition of mortgage interest relief mean it is more difficult than ever for people to buy a home of their own."