Nearly one in four people who were due to retire this year have been forced to put off their plans as they cannot afford to stop working, a survey has found.
Some 22% of people surveyed for Prudential who were scheduled to retire in 2016 have postponed their plans as they cannot afford to give up their job.
Around three in 10 (29%) of those planning to retire this year said they do not believe that their pensions and other savings will give them enough income to support a comfortable life in retirement.
On average, this year's retirees expect to be drawing their pension for more than 20 years.
The findings also showed that more than half (51%) of those who currently plan to retire in 2016 are either already working past their respective state pension age or would consider doing so when they reach that landmark.
This continues a trend seen for the previous three years, in which more than half of people approaching retirement would consider working past their state pension age.
Of those working or considering working beyond their state pension age in this year's survey, 29% would change employers to do so. More than a quarter (27%) would stay in their current job but reduce their working hours, while one in 10 (11%) would stay on full-time in the same job.
Many people had non-financial reasons for considering working past their state pension age. More than half of those already working or considering working past state pension age said they wanted to keep their mind and body active.
One in three (34%) said they did not feel ready to retire and 41% enjoyed their work too much to give it up.
And one in six (16%) of those who have put off retirement said they never want to retire at all.
Of those considering working beyond their state pension age, 7% would like to start their own business while one in eight (13%) would like to try earning money from a hobby.
Stan Russell, a retirement income expert at Prudential, said: "With this year's retirees preparing to spend an average of 20 years retired it's understandable why they now see giving up work as a gradual process rather than a one-off event.
"However, for everyone who can choose their retirement date there are some who have no choice because they physically can't continue at work, and others whose financial situation forces them to stay on.
"Anyone looking to give themselves the greatest degree of choice of when to give up work should be trying to save as much money as possible as early as possible during their careers."
The research was carried out among more than 9,000 people aged 45 and over, including 1,000 people planning to retire in 2016.
The Government's landmark drive to automatically enrol people into workplace pensions and encourage a stronger retirement savings culture started in 2012.
So far, there are signs it has been a success with nine in 10 people staying in the pension they are placed in and take-up being particularly strong among younger people.
Companies are being brought on board automatic enrolment in waves, with the biggest firms having started first. Smaller employers, which tend to have less experience of pensions and explaining their benefits, are being brought into the automatic enrolment scheme.
A Department for Work and Pensions (DWP) spokesman said: "We know that many people are not saving enough to maintain their standard of living in retirement. That's precisely why we introduced wide-ranging reforms to make pension saving easier, clearer and more sustainable.
"From introducing the new state pension, safeguarding the triple lock and encouraging millions more to save through automatic enrolment, we are committed to helping people have a financially secure retirement."
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Retirement postponed by 22% of people who were due to stop working, says survey
Pension experts at Mercer have identified the countries with the best pension systems. At number 10 is Singapore.
The system is based on the Central Provident Fund, which covers everyone in a job. Some of the cash can be withdrawn during your working life, and a prescribed minimum drawn down at retirement as an income.
Overall, Singapore scored 65.9 out of 100. It fared well on sustainability measures, and integrity, but relatively low incomes in retirement dragged its combined score down.
The UK scored 67.6 out of 100. The system was ruled to have great integrity, and good incomes in retirement. The overall scores were also up from the year earlier, as auto-enrolment was rolled out further, bringing more people into workplace schemes.
The researchers, however, were worried about how sustainable the system would be in the future. They called for an increase in minimum pensions, and added that more people ought to be encouraged into workplace schemes and persuaded to contribute more to their pension. They also wanted to see more people saving privately for their pension, and working later in life.
In Chile the state offers means-tested assistance, a mandatory centralised pension for employees to contribute to, and there are voluntary employer schemes.
Chile score 68.2 out of 100. Its highest score was for integrity, with another good mark for sustainability. Relatively low incomes in retirement let it down, and the researchers said the biggest improvements would come from raising the contribution levels.
Canada has a universal flat-rate pension - with a means-tested supplement. There’s an earnings-related pension based on lifetime earnings, plus voluntary workplace and private schemes.
It scored 69.1 out of 100. Its best score was for incomes in retirement, while it also performed well for integrity. Its only relative weak point was how sustainable it might be for the future - particularly because older people don't tend to stay in work.
Sweden has an earnings-related system with notional accounts - although this system was introduced in 1999 so it’s still in transition from a pay-as-you go system to a funded one. There’s also a means-tested top up.
Sweden was given 73.4 out of 100. It scored excellently for integrity, and well for sustainability. The overall score was brought down by incomes in retirement, and the researchers called for more workplace and private pensions.
Switzerland has an earnings-related public pension, a mandatory occupational system and voluntary private pensions.
It scored 73.9 out of 100. It fared well for integrity and reasonably well for incomes in retirement. The researchers just questioned its sustainability.
Finland has a means-tested basic state pension and a range of statutory earnings-related schemes. It scored 74.3 out of 100.
It had high integrity scores, with a less positive result for incomes in retirement, and a surprisingly low score for sustainability. The researchers called for higher minimum pensions, higher mandatory contributions and encouraging people to work longer to improve sustainability.
The Netherlands has a flat-rate public pension and quasi-mandatory earnings-related occupational schemes - which are industry-wide defined benefit schemes based on lifetime average earnings.
The system scored 79.2 out of 100. All its scores were high - particularly for the integrity of the system.
The system in Australia consists of a government scheme, a mandatory employer contribution into a pension, and additional voluntary contributions from individuals.
It benefits from the fact that all workers have been automatically enrolled in their company pension schemes for some time, so participation rates are high. The minimum contributions have also been raised recently, which means workers are building reasonable retirement incomes. It had an overall score of 79.9 out of 100, with the only question mark being over sustainability.
Denmark’s system includes a basic state pension, means-tested state top-ups, a fully funded defined contribution scheme and mandatory occupational schemes.
The researchers said it was "A first class and robust retirement income system". It scored 82.4 out of 100, with high marks across the board.