The name “carpetbagger” was first used disparagingly by a former chief executive of the Woolwich, one of the societies whose flotation will pay out this year. But carpetbaggers are growing proud of the term, seeing conversion as a chance for small investors to benefit in ways that are usually reserved for the rich and privileged.

Carpetbaggers are also at pains to remain anonymous, since building societies are doing everything they can to prevent them from joining, even returning cheques in many instances. Societies are also raising the minimum sum for opening accounts from #163;l00 to as much as #163;2,000.

Chief carpetbagger is Michael Hardern, a mathematical sciences graduate who has worked as a butler for “most members of the Royal Family”. He has set up the Members for Conversion group, which now has 10,000 members. To date, he has been thrown out of 35 societies - and had his accounts closed and cheques sent back.

An English teacher in a South of England secondary school, who joined Harden’s organisation, has opened accounts in 20 societies and says half of the staff are doing the same. This year he is set to gain from the conversions of the Woolwich, Halifax and the Northern Rock.

He first realised the benefits of carpetbagging when he lost out with the Cheltenham and Gloucester. He says: “I was a borrower and having first announced they would pay out to everybody they decided to only pay savers. I realised then what I was missing out on. Four or five are converting this year and there’s about 70 more to go. It’s a one-way bet you can’t lose.” Neither does he have qualms about undermining the “mutuality” of the societies, which he believes does little for small-time investors.

A retired Welsh maths teacher who joined Members for Conversion has opened accounts with 85 building societies - “every single one” in the country. He stands to gain tens of thousands from his initial investment among the societies of #163;3,250. This year alone, for an investment of #163;500, he will gain around #163;4,000 from the conversion of the Halifax, Woolwich, Alliance and Leicester, Northern Rock and Bristol and West, which is being taken over by the Bank of Ireland.

Both teachers have gained substantially from advice offered by Michael Hardern. Top of his list for change is Birmingham Midshires, West Bromwich,Bradford and Bingley, Brittania and the Nationwide. The Yorkshire is another hot tip, and it is still possible to open an account there for #163;100. Hardern believes that most building societies will have converted by the end of the millennium.

But those thinking of hitting the carpetbaggers’ trail now will find building societies less than friendly. The Welsh teacher had his minimum account closed and #163;100 cheque returned from the Marsden (Lancashire).However, he reapplied with more than the minimum and the accounts were reopened. Another way of gaining access to membership is by opening a Tessa.

Although many building societies have jacked up minimum amounts for opening accounts, some carpetbaggers withdraw sums after depositing the #163;100 required for membership. In order to stop this some societies now stipulate that minimum amounts cannot be reduced.

Above all, those with building society accounts of less than #163;100 are advised to top them up in order to gain from future windfalls.

Michael Hardern is urging members of his organisation to join together to nominate directors who will press societies for conversion. He says: “There might be a nice Hovis history feel about mutuality, but 90 per cent of the benefit goes to the top 10 per cent of savers. At the Alliance and Leicester, for example, 50 per cent of savers have accounts of less than #163;1,000. The nearer you are to #163;1,000, the better off you are with a windfall.”

Harden is also pressing for a percentage of the share-out of building societies’ assets to be given to charity.

Members for Conversion, 3 Rathbone Street, London W1P 1AE.

Tel: 0171 255 1079