People who are divorced or separated are even more pessimistic about their finances, with 36 percent expecting to work indefinitely.
"Life expectancy in many countries is rising fast and hopes of retiring at 60 look increasingly unrealistic. Governments are raising the official pension age," says Simon Williams, group head of wealth management at HSBC. "Many company schemes are in deficit and employers, hit by rising costs, have backed away from guaranteed pensions. Responsibility is falling more and more on individuals."
Those that have already retired are finding themselves worse off than they expected, with 39 percent saying they weren't adequately prepared financially - and 35 percent saying they'd only realised this after they had retired. This is partly because there's a tendency to underestimate outgoings, with 52 percent saying their expenditure had remained the same and 17 percent saying it had risen.
On average, people say they have enough savings to last them seven years - compared with an average of 19 years spent in retirement. In the US, by contrast, people say they have enough savings to last them 14 years.
The survey findings back up government concerns that the country's growing life expectancy is putting pressure on pensions. In an attempt to reverse a slide in private pension saving, it last autumn started introducing automatic enrollment in workplace pensions for employees of larger companies. Over a million people have already been enrolled.
Free guide: Investing for income at a time of low interest rates
HSBC advises that people approaching retirement should be realistic about their outgoings, and in particular bear in mind continuing responsibilities to family. They should, ideally, have more than one source of income to spread the risk. And, above all, they shouldn't be in any rush to give up work: nearly two thirds of those surveyed who were working part-time said they wished they'd stayed in full-time employment longer.
"Today's workers should prepare for retirement as early as possible to have some certainty for retirement," says HSBC head of wealth management Christine Foyster. "Life is full of reasons to prioritise short term spending over longer term planning, but the sooner people start saving, the less likely they will have to rely on working in old age."