Boston Edison, in what may be its last stand against the Medical Area Power Plant, argued in court yesterday that the Boston Redevelopment Authority (BRA) may have committed legal errors in granting approval for the power plant's construction.

Edison lawyers told Suffolk Superior Court Judge John McNaught that the BRA may have violated the law on several procedural matters when it voted approval for the $50 million project last November.

Slim Pickins

The chances of the challenge succeeding are slim--the Boston Redevelopment Authority has never lost a court challenge over its procedural matters.

And, in what must be considered a setback for Edison, McNaught ruled yesterday that the power company may not present any new evidence that was unavailable to the BRA when it gave approval to the plant.

Because of the length of Edison's arguments, lawyers from the Boston Redevelopment Authority and the medical institutions involved will not be able to present their cases until the court reconvenes on May 24.