Breakdown insurance for electrical goods can cost more than half the price of the appliance itself and is often unnecessary, according to Which? research.

Extended warranty cover is often sold for ‘peace of mind’, Which? claimed, but a replacement item often only costs a little more than the warranty.

An investigation by Which? found a smoothie maker being sold for £17.50 carried an optional three-year warranty for £14. The three-year warranty for a DVD player being sold for £45 cost more than half the price, at £25.

According to the report, improvements in product reliability often mean shoppers never need to claim on the cover anyway. Shoppers also have statutory rights obligating stores to repair faulty goods, in some cases.

Peter McCarthy, senior lawyer at Which? Legal Service, said: “Don’t let a seller have you believe that your legal rights end with the guarantee. The seller will be liable if the goods it sold you aren’t of satisfactory quality.”