Collyer Bristow will face the action in the new year following their involvement in an investment scheme known as Innovator One.
The firm is already facing a multimillion-pound claim from Rangers' liquidators, Cohen & Stephen.
The allegations centre around former partner Gary Withey's role in the buyout.
In May, Mr Justice Hamblen threw out the claims of the 555 Innovator One claimants.
However, in the court of appeal last week, Lord Justices Longmore and Lloyd granted an appeal against the ruling.