Former Southampton chairman Rupert Lowe will not support the proposed takeover of the club by hedge fund Sisu Capital.
Former chairman Lowe remains one of the club's major shareholders
The proposed deal, revealed in October, would see Sisu take a majority stake in the Championship club's parent company, Southampton Leisure Holdings plc.
Lowe said he had made suggestions to Sisu about the structure of the deal.
But he told BBC Radio Solent: "They are adamant that they will not change their outline, so for now they will not receive our support."
Sisu's proposed offer would be executed by means of a placing of new shares at 40p per share - 20% below its current share price - but it needs the backing of 75% of shareholders.
Lowe stood down as chairman in June 2006, but remains a major shareholder in the club.
He has met with Michael Wilde and Leon Crouch, who are also former chairmen of the football club and major shareholders in Southampton Leisure Holdings, to discuss their position.
The trio are yet to meet representatives of London-based Sisu, but Lowe said there was "no point in meeting" at this stage.
The proposal is unlikely to attract the necessary 75% backing if Lowe, Wilde and Crouch do not support it.
A club spokesman said they had procured an offer of investment, and it was up to the shareholders whether they wanted to accept that offer, while Sisu declined to comment.
Lowe, Wilde and Crouch announced in late October that they would not back the deal as it stood, and were seeking answers to 10 questions about Sisu's proposals.
At the beginning of November, the club issued a statement warning that players would have to be sold in January "in the absence of significant new investment".