Millions of people have gone to the polls to cast their votes in elections in England, Scotland and Wales.

But few will have known that the personal details they divulged to be eligible to vote in the first place are available for sale.

The electoral register can be bought by anyone who cares to buy it. It means that a surprising amount of information about a large number of us is also readily accessible.

It is particularly useful for companies such as direct marketers and credit agencies. Many members of the general public, however, may be less sure they approve.

Public protection

The data protection registrar, Elizabeth France, has no doubt there is something wrong with such a practice.

George Howarth: Concerns about poor turnout

"One of the basic principles of data protection is that information obtained for one purpose should not be used for another. You and I have no choice but to give our name and address and if we don't we suffer the risk of criminal penalty.

"Then there is a duty on the electoral role officer to sell the register and it can then be used freely for secondary purposes and my guess is that most people do not appreciate that when completing their electoral role form," she said.

The government too has misgivings. Government minister George Howarth is worried about falling turnouts at elections.

He thinks some people are not registering to vote because they do not want their details to be bought by direct mail companies or organisations checking if they can pay their bills.

But on the other side, the companies who use this information are just as concerned by suggestions that its availability should be withdrawn.

Invaluable information

One computing group in Crawley, which acts as a direct marketing bureau, says that the electoral roll is a vital tool. It can, for instance, be used to find out where people have gone when they move house.

Pensions and insurance firms in particular need to know your address. They may, after all, owe you money.

Computers check how many years people with a particular name have been registered to vote at their current address. If they have only be registered a year, they could be the person being searched for.

Access to the electoral roll cuts junk mail

The roll is also used for weeding out duplicate entries in mailing lists, saving companies money and their customers irritation. The effect, according to the industry, is less junk mail.

The operations manager of the computing group's parent company is Tony Masters. He says having access to the electoral roll saves his companies and clients millions of pounds a year.

"All our calculations indicate that use of the roll commercially for the assessment of risk and suppression of names from mailings is extremely valuable to industry generally," he explains.

The data protection registrar says that when people register to vote they should have the choice of taking their name off the published register.

But that would make it much less useful for all the many companies out there who rely on the information it contains.