Soccer/Manchester United power struggle: Alex Ferguson's position at Manchester United came under more pressure yesterday when it emerged that John Magnier and JP McManus, the club's major shareholders, will soon have up to three representatives on its plc board.

Cubic Expression, the investment vehicle they have used to build a stake in the company, also announced yesterday that it had raised its holding in the club by 3.4 per cent to 28.89 per cent.

Ferguson will be dismayed the man he is suing for up to #100 million has moved into such a position of strength in the boardroom.

Last night the development was described as "disastrous" by groups representing the club's shareholders and supporters, who are planning a major protest at next month's Cheltenham racing festival. Yet they, like everyone else associated with England's biggest club, will have to get used to the idea after Cubic Expression spent another #22 million on shares yesterday.

If it were to raise its holding above 29.9 per cent, Cubic Expression would be obliged to offer to buy out all the other shareholders, something it has no plans to do. The main ambition has been to exert greater influence. However galling it may be for United's plc chairman Roy Gardner and the chief executive David Gill, and however significant the threat of a new regime causing serious divisions, they have been forced to acknowledge they are no longer in a position to keep the Irish at bay.

As yet, it is not clear whether it would mean non-executive directors such as Maurice Watkins, Ian Much and Philip Yea being forced off the board or whether the new members will simply be added to the existing eight.

By taking an active role in the club, the Cubic pair are effectively backing Ferguson into a corner in his dispute with Magnier over the breeding rights for their racehorse Rock Of Gibraltar. The United manager is determined to take the case to the High Court in Dublin, a process that could take another 18 months, but the ramifications are serious enough now that it could be the difference between him staying in a job or being forced out.

Ferguson, meanwhile, has held talks with Dermot Desmond, the largest individual shareholder at Celtic, a United shareholder and a close associate of Magnier. They met in London after a disagreement relating to Liam Miller's move from Celtic to United. The legal dispute was not thought to be on the agenda, but it would be remarkable if the issue was not mentioned.

Such has been the hostility between the two factions, particularly since the turn of the year, that Ferguson is under no illusions about how difficult Magnier and McManus could make life for him if they were pulling the strings on the board.

Under pressure from Cubic, the club's finance director Nick Humby is already undertaking an in-house investigation into some of United's recent transfers.

As well as the case involving Rock Of Gibraltar, lawyers for the two businessmen are investigating a possible claim of defamation from a press conference 13 days ago at which the manager claimed bin-bags and mail had been stolen from the home of his son Jason. They have yet to receive a transcript of the press conference despite requesting it last week.

Gill and Gardner have realised there is no ground to be gained in antagonising two shareholders of such financial power and their recent exchanges have been more conciliatory. In particular, United's response to Cubic's 99 questions about recent transfers, payments to agents and other issues of corporate governance encouraged Magnier and McManus by its tone, even if it failed to answer all the points to their satisfaction.

They will be less impressed by the plans of a group called United 4 Action who have sought official permission for a protest at Cheltenham on March 18th, an event featuring horses owned by Magnier and McManus. "We want to get the message across that we don't want them at our club," said the organiser Sean Murphy.

Oliver Houston, of the pressure group Shareholders United, accused Magnier and McManus of "trying to mount a takeover through the back door".

He added: "Having their representatives on the board would be disastrous. Given the splits between Cubic and the existing board, the potential for leaks and fall-outs is enormous. Manchester United is a well-run business already, so what can Cubic bring to the table but disruption?"