Aaron Strutt, of Trinity Financial, a mortgage broker, said: “At a time when so many homeowners are earning virtually nothing on their savings, their cash could be working harder with a decent offset mortgage. They’re particularly useful for the self-employed while there is so much economic uncertainty.”    

Most high street banks pay as little as 0.01pc on easy access savings accounts. Meanwhile, the average two-year mortgage fix is 2.3pc.

Over a year, £50,000 savings in an easy-access account would reduce to £47,905 in real terms at the current rate of inflation.

A £150,000 mortgage would cost £658 a month on the average two-year fix. However, if the £50,000 savings were instead offset against the mortgage, this would reduce to £439.

Using this method the homeowner would save £15,792 in interest payments over the course of a 25 year mortgage term, compared to the £125 the savings would have earned in an easy-access account.

Banks have been slowly pulling these deals over the past two months. There are now 145 deals available, 10 fewer than last month. The average offset mortgage rate has also climbed, from 2.35pc to 2.45pc, according to Moneyfacts, an analyst.