According to the research, the average amount saved by those with a cash ISA over the last two years is £3,100, when the tax free total they could have put away is £6,600, which just six per cent of savers managed.

The survey also found that almost a quarter of people have no savings at all, and that 36 per cent have less money in savings now than they did two years ago.

Commenting, Kevin Mountford, head of banking at moneysupermarket.com, said: “A quarter of people have no money at all put aside, which shows just how serious rising unemployment will become over the coming year.

“Those with savings would be wise to make use of their cash ISA allowance. Most accounts allow you to withdraw cash without any loss of interest or tax implications should you need the money at a later stage.”

According to moneysupermarket.com’s calculations, someone who had invested their full Cash ISA allowance each of the last 10 years would have around £41,600 saved now, £11,000 of which would be in interest, which is a bonus of £2,700 compared to the same amount saved outside of a Cash ISA.

Mr Mountford added: “It’s not too late for anyone with spare cash to put some away in an ISA. People have until the end of the tax year – April 5 – to squirrel away up to £3,600.”

Compare ISA deals »

© Fair Investment Company Ltd