VISTA - A San Diego attorney continues to challenge Wal-Mart as the company tries to expand its retail store in east Vista into one of the region's first Supercenters.

On Friday, Neal Maguire of the law firm Latham & Watkins appealed the Vista Planning Commission's recent decision to allow Wal-Mart to add roughly 30,000 square feet to its retail store on University Drive. The appeal means the issue now goes to the Vista City Council, which appears likely to approve Wal-Mart's plans.

The company's Supercenters, which include full grocery stores, have been praised by consumers drawn by the chain's low prices. However, critics say the stores pay workers far less than unionized supermarkets and harm the environment through excessive traffic and noise.

This marks the second time Maguire has appealed the Vista project in six months. His first, which triggered the Feb. 5 Planning Commission hearing, came after city staffers OK'd the retailer's proposal in August.

By challenging the project at each stage, Maguire appears to be exhausting his administrative remedies - a required step before filing a lawsuit. Each appeal adds another layer of city review and weeks of delay.

The City Council hearing is slated for March, a city official said.

Wal-Mart spokesman John Mendez said Monday that, despite the delays, the company will press forward with its plans.

Wal-Mart, the world's largest retailer, is no stranger to opposition. Unions representing grocery workers, neighborhood groups and environmental activists have aggressively fought the company's projects in other communities, occasionally turning to the courts.

In Vista, little is known about the person who hired Maguire. The attorney has said only that he represents a city resident named Isidro Zamora. Attempts by the newspaper to locate Zamora have been unsuccessful.

Mendez suggested Monday that special interest groups are probably also at work in the Vista case.

He said it's unfortunate that such forces are "interfering with these families' freedom to shop where they want and to buy groceries at a low price."

"Given the state of the economy, you'd think their actions would be in support of working families who are just trying to stretch their dollar," he said.

Maguire, whose office was closed Monday for the Presidents Day holiday, could not be reached for comment.

In recent months, the attorney has sent detailed letters to the city, alleging that Vista's handling of Wal-Mart's application has violated California's strict environmental laws and been rife with procedural laws.

Thus far, there's been little public outcry about the store expansion. At the Planning Commission hearing, all of the public speakers - except Maguire - were pro-Wal-Mart.

Mayor Morris Vance said Wal-Mart isn't likely to see opposition from City Council members next month because all of them knew the store would grow one day. The original plan for the building, which city officials approved in the early 1990s, included space to expand, he said.

"I think they have a right to complete their project," Vance said.

- Contact staff writer Craig TenBroeck at (760) 901-4062 or ctenbroeck@nctimes.com.