Solicitors yesterday issued proceedings against the club at the High Court in Leeds on behalf of bondholder Jane Duffy, leader of the Save Our Seats campaign, which was mounted when the club announced plans to move up to 4,000 fans.
Ms Duffy is seeking an injunction to protect her current seat and a ruling that the pounds 500 bond she bought in 1994 entitles her to a specific seat. Mr Justice Hopper, the presiding judge of the north-east circuit, will sit at the first hearing on Tuesday.
Ms Duffy's solicitor, Richard Cramer, said: "There could be as many as 600 bondholders involved, and what they are seeking is to stay in their seats. That is what they believed they were entitled to when they purchased their bonds.
"The bond scheme is a very, very good way of raising money in the short term, and that is what Newcastle did. But they have got to stick to their part of the contract and they have clearly not done so."
Bondholders believed they had purchased the right to a specific seat for 10 years but the club insists that the guarantee extends only to a seat. Fans made a stand-up protest during United's televised 2-1 victory over Derby on 25 October.
The club claim to have satisfied the vast majority of those affected with other seats and work is currently in progress to increase stadium capacity to 52,000 by August - but the row refuses to die down.Reuse content