Jonty Bloom: "Supporters of the Building Society movement claim that savers and borrowers will lose out"

Members are gathering at the group's West Yorkshire head office to cast their votes and an estimated 1.5 million people have responded to a postal ballot.

The result will be unveiled at the group's annual general meeting at around 1500 local time (1400 GMT).

If members vote to convert to a bank it could trigger an average windfall of up to £1,000 for millions of B&B's customers.

However, the management of the Bradford & Bingley are keen for it to stay as a building society. They claim they will be able to continue to offer lower borrowing rates and higher saving rates.

Windfalls on offer

Other building societies could come under threat

If the vote does go against the building society then the board is likely to either float on the stock market and give its members free shares, or accept a takeover bid. Either way it would trigger windfalls.

The turn-out has been high - with an estimated 60% of the 2.5 million members eligible to vote, registering their opinion.

If B&B converts to a bank it would put increasing pressure on other societies to follow suit and the decision could mark the beginning of the end for the building society movement.

However, if B&B can overcome the threat of conversion it will deal a significant blow to the carpetbaggers - people who have joined building societies in the hope of receiving large windfalls.

Too close to call

The vote remains too close to call.

The decision has attracted intense media speculation - but newspapers disagree about the result.

The Sunday Times and Sunday Telegraph said members had voted in favour of converting B&B into a bank, while the Financial Times, Independent on Sunday and Mail on Sunday said the vote had gone the other way.

Stephen Major, a plumber who lives in Northern Ireland - called the vote on conversion.