Firing Line: Sir Derek Wanless

A retail banker - he was the former boss of NatWest - his expertise lies perhaps more in savings, current accounts and debit cards. Yet he has started to voice some startling conclusions - apparently we should abolish the retirement age altogether.

This is perhaps easier for him to say publicly than those in executive positions, and comes just weeks after Lord Adair Turner said he had perhaps been too cautious in his first pension analysis, and that the retirement age should be 70.

Nonetheless, the concept makes sense to Sir Derek: no firm retirement age could give people the flexibility of retiring when they want, dependent on their pension fund, their lifestyle and their interests in life.

He says: "What we are going to see in the future is much more flexibility. People will say: 'I know what I want to do, I want to stop work at a certain age, I accept I will have to make my own arrangements,' or they might say: 'I'm very happy to work a bit longer, some of that work might change, I'm going to adjust my life, and I'm going to have to look after myself’."

Of course, longevity has become one of the more taxing concepts of modern life, challenging for the officials who need to make sure people can look after themselves, and the financial services companies that have promised to pay for those who already thought they were.

While people may have wanted a longer life, and medical science and changing lifestyle have made that possible, the long life on offer is not without its complications - not least because of deteriorating physical and mental health.

The problem, says Sir Derek, is that increasing longevity is almost impossible to predict.

He says: "It is quite hard to get a definitive answer. The actuaries thought it could not carry on, but it is not just carrying on, it has increased. We are not talking about dramatic changes in longevity, but a consistent improvement.

"There are lots of effects in both directions, though with the evidence that we are seeing, lifepsans have been increasing more rapidly in the last few years. If anything, the rate of improving is increasing at a time when people were assuming that the increase would slow.

"But then, it is not certain that it will be continuing, as you have pandemics and obesity - obesity has the potential of reducing longevity."

According to official figures it took a century before 1985 for the life expectancy of men age 65 in England and Wales to increase by 2.9 years. Yet in the two decades from 1986 to 2006, life expectancy for men age 65 in the UK has increased by 3.7 years.

The subject of longevity is an interesting one for Sir Derek, not least because of his own numerous positions since retiring from NatWest, where he was chief executive for seven years, but also because of a post-NatWest report he compiled a few years ago.