Welcome to the scrapheap, Mr Blair, says Help the Aged in a deliberately provocative campaign to highlight the plight of many over-50s. To mark the fact that Tony Blair will be 50 on Tuesday, Help the Aged will send him a doom-laden birthday card which is also being sent to every MP over 50.

Their spokeswoman said: "Mr Blair will be warned that he may be denied certain health treatments, his ability to drive a car may be questioned and access to social care could be limited because of his age. These are just a few of the realities of age discrimination."

In an interview with Saga magazine, Mr Blair admitted: "I've been dreading 50." But although, as our panel shows, he is a lot better placed than the vast majority of 50-year-olds, the fact is that as the population grows older, the over-50s are becoming a political force.

In 2001, the over-50s made up a third of the UK population, a figure that is due to rise to 38 per cent by 2016 and 40 per cent by 2026. The 2001 national census revealed that the UK has more people aged over 60 than under 16 for the first time.

But they are not only powerful in sheer numbers: the over-50s have more financial clout than any other section of the population, too. Their collective wealth adds up to £175bn, and 90 per cent own their own homes, of which 72 per cent have no mortgage. The over-50s hold 60 per cent of all UK savings and investments, and 85 per cent of them have private pensions. And they have not let the internet pass them by: 80 per cent of all e-commerce transactions are carried out by the over-45s.

At Firhall Village near Nairn in Scotland, a £10m residential community of 26 gated properties has been created which specifically excludes those under 45, except for holiday visits.

But, while 50 is not a crucial age in terms of tax breaks, it does bring people within sight of retirement, whether that is to be at 60, 65, 70 or more. So it is a convenient time to see where you stand and whether to take action to put things right.

Campbell Edgar of Bloomsbury Financial Planning, who reached 50 last year, said: "First of all, enjoy yourself – life begins at 50. If you want to, at 50 you can start to draw down your pension and stop work without penalty. If you don't have much money, you can claim the new Working Tax Credit. Go to a solicitor and draw up an Enduring Power of Attorney in respect of yourself, then if you get knocked unconscious in an accident at any time your wife or other close person can make decisions for you."

Patrick Connolly of the financial adviser Chartwell said: "There is no magic wand, you should be doing a regular review anyway, on an on-going basis. Priorities are going to be changing once you are over 50, in terms of investments. You are moving from a growth basis to reducing risk and looking to be able to take income from investments. So review your savings, to make sure you are hitting those objectives. If your investments are not suitable, find ones that are.

"On the protection side, consider a long-term care policy or at least look at the options to see what might be suitable. And you may not have a definite retirement date, but think in terms of what age would be right for you and what sort of income you will need. If you are short of cash, look at releasing some of the equity in your house. General insurance is cheaper for the over-50s, especially car and home insurance, because they are more careful. And Saga does cheap share dealing."

As Mark Dampier of adviser Hargreaves Lansdown pointed out, the good news about reaching 50 without any financial planning is that nowadays you will probably still have at least 20 years to go before you retire. "So there is less of a rush than there used to be, particularly with regard to the old rule about having the same percentage of your wealth as your age in low-risk fixed-interest bonds. If you give yourself a 20-year timescale, it may actually be wrong to have as much as 50 per cent of your money in bonds, because the odds are that you will miss out on one or more bull runs in the stock market. But you should certainly be thinking along those lines, looking at your asset allocation between shares, bonds, property, cash and alternative or exotic investments such as art, wine, collectables or funds invested in Asia or South America."

Mr Dampier is a keen advocate of Self-Invested Personal Pensions (Sipps), where you decide what your fund is invested in, within limits laid down by the Inland Revenue. You cannot, for example, put your house into your Sipp, but most orthodox investments will qualify.

Maria McEnery of Help the Aged said: "The first thing is to speak to a financial adviser to ensure that you are on track with saving for retirement. They will also be able to advise of products geared for older audiences.

"On a very practical level, it may be worth speaking to a specialist insurer. Over-50s may find it difficult to get sensibly priced travel or motor insurance – or when they are older find that they are unable to secure it at all. Conversely, older people may also benefit from better premiums as a result of their age if they shop around. Many specialist insurers, such as Help the Aged Insurance on 0800 41 31 80, recognise that older people are often more security-conscious so reflect this in the premiums."

It is worth thinking about long-term care. Owain Wright of the Care Funding Bureau, an independent financial adviser (IFA), says: "Buying a care fees annuity swaps the unknown cost of providing long-term care for an amount known at outset, no matter how long the policyholder lives." Also, if the annuity is paid directly to a nursing home, the income is tax-free, meaning your money goes further.

There are 23 benefits that older people may be entitled to, but around £1.9bn goes unclaimed. Help the Aged has a leaflet, Can You Claim It, on www.helptheaged.org.uk

Checklist

* Draw up a budget, listing income and spending, so you can see whether you are generally saving or drawing on savings.

* Check how long you are likely to live. Plenty of websites calculate this, and even a rough idea will help you to plan.

* If you have savings, check that they are achieving what you want. You will gradually need to switch to income-producing investments as you near retirement.

* Write a will. You can change it at any time, but it will focus your mind on where you want your money to go.

* Grant someone you trust Enduring Power of Attorney. This will not be triggered unless your mental powers fail, but it will mean you will have a say in how your affairs are managed.

* Inheritance tax. Talk to a financial adviser or planner about how to minimise it, either by giving money away – or spending it!