The number of people who have had mortgage applications turned down has soared by 60% during the past six months, according to a survey.

A combination of higher interest rates and tighter lending criteria affecting would-be borrowers in the higher-risk or sub-prime market are cited as reasons for the rise.

The research by financial website MoneyExpert.com indicates the total number of would-be homeowners turned down for a loan increased to 738,000 in the past six months compared to 463,000 for the previous six months.

The UK-wide figures come as borrowers have been hit by three recent interest rate rises and banks suffer from the collapse of the sub-prime mortgage market in America hitting financial institutions around the world.

However, lenders in Scotland said the mainstream market remained strong and only sub-prime borrowing was affected.

Given the current climate, lenders said it was to be expected that more of those deemed a greater risk will be refused.

A spokeswoman for Halifax Bank of Scotland: "We haven't made changes to our criteria. If that is a trend it is most likely to be in the sub-prime market, and not HBoS customers as we are a mainstream lender."

Martin Smith, financial services director with Glasgow-based estate agents Clyde Property, said: "We deal with around 1000 mortgages a year and there is little or no difference in the number declined.

"We understand between 20% and 30% of applications in the sub-prime market are being turned down though but the mainstream market is business as usual."

Sub prime market includes people with adverse credit history or court judgments, who until recently had few problems securing home loans.

Cash for these type of loans is now in short supply following the high default rate in the US. Sue Anderson, spokeswoman for the Council of Mortgage Lenders, said: "It is highly likely there will be a higher proportion of rejected applications.

"There is less funding available for sub-prime market and in the mainstream market in light of the current market conditions there will be a higher degree of scrutiny. This is in line with what we would expect.

"The more marginal products, like high loan-to-value lending, will be less available."

According to MoneyExpert.com, younger people, those with low or no deposits and those seeking to borrow high multiples of their salary are most likely to be rejected, while experts say the market is still in good shape.

Would-be borrowers aged between 25 and 34 account for half of all people who were turned down.

Sean Gardner, chief executive of MoneyExpert.com, said: "Life is tough at the moment if you are applying for a mortgage.

"The financial environment is far more stringent than in the summer of last year and people need to be prepared for rejection."

The Intermediary Mortgage Lenders Association (IMLA) said the fundamentals of the UK mortgage market are sound and conditions are slowly returning to normal.

Meanwhile house prices rose by 0.5% during August as the property market continued to show signs of slowing down, according to official government figures.

The gain, which pushed the average cost of a home in the UK up to £219,528, was down on the previous month's jump of 2%.