Homeowners are at risk of paying over the odds for their mortgage due to the vast array of "complex and unclear" fees and charges attached to such deals, according to Which?

The consumer group found more than 40 different names for fees and charges across the market, including "administration fees", "application fees", "assessment fees", "arrangement fees", "booking fees", "product fees", "reservation fees", "lenders' fees", "completion fees" and "mortgage questionnaire fees".

It said that since 2009, the year the Bank of England base rate fell to its historic 0.5% low, the average arrangement fee cost has almost doubled, from £878 to £1,588.

Which? is calling for Chancellor George Osborne to use his forthcoming Autumn Statement to make it easier for people to find the best mortgage deal by making overall costs clearer.

The consumer group, which is running a "stop sneaky fees and charges" campaign to put an end to confusing and hard-to-compare charges across the financial sector, said the range of fees attached to mortgages make it hard for borrowers to compare the total cost with other deals.

Its research had found that, for example, someone borrowing £100,000 over two years could potentially save around £1,500 if they took the full set-up fees into account rather than just concentrating on the deal with the lowest rate.

Which? found a wide variation between lenders in the cost of the same fees, which it said suggests that fees do not always reflect the true cost incurred by the lender.