Over £1.3 trillion is languishing in savings accounts paying less than 50% of the Bank of England's base rate of 4.5%, according to a new report.

Around three in four pounds of UK savers’ cash is sitting in these low interest savings accounts, according to the report from savings platform Flagstone.

Close to half (48%) of UK savers surveyed for the report did not know what the interest rate was on their savings account.

A third (29%) had used the same low interest savings account for over 11 years.

Claire Jones, head of strategic partnerships at Flagstone, said advisers need to do more to help Britons think harder about where they put their cash savings.

She said: “Advisers have an opportunity and a duty to mobilise their clients and help them think harder about cash as an asset class in its own right - one that offers competitive, risk-adjusted returns alongside their investments and pensions.

"As an industry dedicated to preserving and growing people’s wealth across the most diverse range of opportunities, it’s time to help more people optimise their cash opportunities.”

Flagstone has designed a sleeping giant statue made of 2,000 fake bank notes and placed it in the centre of Canary Wharf to warn about the danger of “sleeping savings”.

• OnePoll surveyed 2,000 UK adults in January on behalf of Flagstone.