Murray, which counts Tory trade spokesman John Redwood among its non- executive directors, attacked Leek's handling of the voting process and said it planned to force a second vote. Kenneth Murray, Murray's chief executive, said: "Even if the vote goes our way, I still think it needs a recount."
Neil McFadden, Leek chief executive, said: "It sounds as though he thinks he's lost and he's asking the referee to call the game off... I am fairly confident that we will carry the flag."
Mr Murray claimed that a substantial number of Leek's members had not received a form inviting them to vote. He called for an external audit of the society's records. Mr McFadden dismissed this, saying Leek's database had been validated by accountants KPMG and that the Electoral Reform Society was monitoring the voting.
Murray has bid pounds 30.5m for the Staffordshire mutual, and plans to develop it as an online bank. Today's meeting is scheduled for midday in Stoke- on-Trent.
Yesterday the Chelsea and Skipton building societies, both facing demutualisation votes, said they were considering raising the minimum balances required to open new accounts. Portman Building Society, which has also received a demutualisation proposal, put a block on new customers on Tuesday.