By Michael Robinson
BBC Money Programme
Most major British companies have introduced defined contribution pension schemes over the last decade after having closed their final salary schemes to new employees, but the introduction of these more risky, cash-based pension plans has not been a success.
This is in part because many employees have failed to sign up.
Kelvin and Janet who both work for Boots will receive different pensions
At leading newsagent WH Smith, 82% of eligible employees have rejected the company's defined contribution scheme, leaving abound 14,000 of them without a company pension.
At leading chemist Boots the situation is worse, with 92% or 30,000 eligible employees not signing up.
At Mitchells and Butlers, owners of national pub chains like All Bar One and Harvesters, a staggering 97% of eligible staff have not joined, leaving about 11,000 staff out of the pub operator's schemes.
It is impossible to say whether these companies are typical since many firms refuse to divulge their take-up figures. Debbie Harrison, a senior pensions analyst at the City University's Pensions Institute believes most employers have good reason to keep their figures hidden.
"For a lot of companies it's possibly an embarrassment that, as a caring employer, they have only 20%... of their workforce in their pension schemes," she says.
"It begs the question, 'what are you doing for the other 80%?' and the answer is 'nothing'."
In the UK, where the state pension is one of the lowest in the developed world, company final salary pensions have long provided vital extra income for a comfortable old age for millions of Britons.
Lancashire butcher John Chadwick's son has signed up to his scheme
The low take-up of the new defined contribution pensions means many will face poverty after they retire on the state pension only.
Martin Taylor, chairman of WH Smith's pension trustees, understands why so many employees turn down the schemes.
"The first thing you see is that your take-home pay falls, because some money has been diverted into the scheme, and we all know that people live so close to the edge of their money that they're most unwilling to see this happen. You know, we might be dead, we might win the lottery, why should I not spend this money now?"
Moreover, employers have little incentive to encourage reluctant employees to sign up, according to former Downing Street pensions adviser Dr Ros Altmann.
After all, profits are boosted by the low take-up since most companies only agree to contribute to defined contribution pensions if an employee signs up and contributes as well.
Consequently, she says, "a situation which is developing in many companies where the finance director says 'I don't see much value in putting money into a pension and I can get away without it, so why bother?".
"Individuals don't value pensions and don't really want to put their own money in, and the employer says, 'well if the individual doesn't want to do it I don't need to encourage them to and then I can get away with not putting my contribution in either'," she says.
But even when staff do sign up, there's another major problem.
Dr Altmann says many companies are happy if staff do not join
With final salary schemes, companies typically contributed the equivalent of 15% to 20% or even more of an employee's pay to the pension fund.
But with the switch to defined contribution pensions, most firms dramatically reduced their contributions.
Marks and Spencer is among the most generous offering up to the equivalent of 12% of employees' pay to staff's new defined contribution pensions.
Sainsbury's offers 6%, Next a maximum of 5% and Boots will contribute no more than 3%.
Kelvin and Janet Davies both work for Boots, yet their expected retirement incomes vary dramatically.
Ms Harrison warns of looming disaster
Kelvin joined before the Boots final salary scheme was closed to new employees, so for every £1000 a year Kelvin earns, Boots contributes around £150 a year into the company pension fund to cover the pension he has been promised. Janet, who has signed up to the Boots defined contributions scheme, gets just £30 for every £1000 she earns.
But Boots' 3% isn't the lowest contribution on offer.
Lancashire butcher John Chadwick, which has just won the "Best Small Business in Britain" award, had to offer stakeholder pensions to staff after 2001 when the government required any employer with more than 5 employees to do so.
Yet when asked how many have signed up, he replies "just one", and that is his son.
The low take-up is perhaps not surprising. Like many smaller businesses, Mr Chadwick doesn't offer to contribute a penny to his staff's pensions.
"I don't see how it can be my responsibility to pay a pension." Mr Chadwick says.
"I pay them a good wage, I pay them above what is required by law.
"I can educate them, I can ask them, I can tell them, I can beg them. I can't make them [buy into the scheme]."
If Mr Chadwick was to offer to contribute to pensions, "the customers [would] have to pay more or else I have to lose profit", he says.
"There are only two ways it can come out".
With pension saving from both employers and employees falling alarmingly, a high-powered government appointed commission has been examining ways to avert a pensions meltdown.
Yet no decision will be taken until well after the election despite experts insisting action is urgent.
"We will be heading for disaster," says Ms Harrison.
"If we do not take steps now, it means that people retiring in 20 to 30 years time will be retiring in poverty."
Pensions Panic: All Worked Up was broadcast on BBC Two on Friday 18 March at 1900.