Another 12.5% do not have enough income to save. These include the long-term unemployed, those dependent on state benefits, and many single parents.

That leaves only half the adult population making long-term plans for saving for retirement, whether in the form of an occupational or personal pension or in a Tessa or Pep.

Not surprisingly, saving for retirement increases with age, while the young predominate in the "can save, won't save group", with 58% being under 35.

The other major group not saving are married women. Women make up two-thirds of the non-savers, with many apparantly relying on their husband's pension to fund their retirement.

Even among those who are saving, only one in five say they are in complete control - with a retirement plan and enough savings to achieve it.

The IFA argues that the lack of savings by such a substantial group of the population means there is a strong case for compulsory stakeholder pensions.

The government is committed to bringing in this new tier of funded pension provision, with a White Paper promised later this year.

But it has not yet said whether it will require people who do not save for retirement at present to sign up to the new pension plan.

The problem is that the private sector is widely distrusted by the public after the pension mis-selling scandal.