THE public spending watchdog has urged the Government to step up its efforts to tackle Britain's retirement savings crisis.

The National Audit Office (NAO) raised concerns there was no single joined-up programme to encourage people to save for their later years.

It warned of "significant consequences" to the taxpayer of people living for longer, which will increase the burden of social and healthcare needs.

Projections already predict a rise in spending on state pensions and pensioner benefits as a share of the UK's GDP from 6.9% in 2011/12 to 9.5% in 2061/62 but the NAO said even current forecasts may be too optimistic.

The Government also expects state pension reforms and its landmark programme to automatically place people into workplace pensions will reduce the potential long-term spending liability. But in reality, the long-term costs for Government remain highly uncertain, the report warned.

The Treasury leads overall savings strategy and the Department for Work and Pensions (DWP) oversees workplace saving but the NAO said it was concerned that without a "whole system view", there was a lack of coherence and accountability.

Amyas Morse, head of the NAO, said: "What is needed is for the Government to take a more holistic view of its portfolio of interventions, how they interact and their relative costs and benefits. It should be more active and effective in influencing citizens to save more and plan more effectively for retirement."

The number of pensioners in Scotland is expected to rise by 26% by 2035, compared with a 7% increase in the working population.

But across the UK there are already an estimated 10.7 million people, equating to two-fifths of the working-age population, not saving enough for the income they want in their old age.

TUC general secretary Frances O'Grady said the report showed that Government policies on retirement incomes were being "mismanaged".

A UK Government spokesman said: "We are collaborating successfully to improve fairness, control costs and boost retirement saving."