Wal-Mart Stores Inc. has commissioned a poll, collected thousands of signatures for a petition and is assembling a coalition to persuade the Montgomery County Council to vote down tough proposed zoning restrictions on its biggest stores.

Wal-Mart's lobbying message: Restrictive zoning rules are anti-consumer, and they deprive shoppers of choice and convenience.

"We don't want to lose these battles," said Mia Masten, a Wal-Mart spokeswoman, who said the proposed restrictions could have a ripple effect throughout Maryland, blocking the chain's expansion. "It can have a chilling effect on growth."

The Bentonville, Ark., retailer has no immediate plans to build a supercenter in Montgomery County, but it has not ruled out the possibility, Masten said. The chain has two stores in the county -- a Wal-Mart in Germantown and Sam's Club in Gaithersburg.

The proposal, which is expected to be introduced in September, would require chains to obtain a special exemption to build a store larger than 130,000 square feet, a description that fits Wal-Mart's supercenter format: a 145,000- to 210,000-square-foot retail behemoth with 36 departments.

Facing criticism from inside and outside the county government, the council Monday revised an earlier proposal that more narrowly targeted Wal-Mart supercenters. That proposal would have required special zoning exemptions for stores that are larger than 120,000 square feet and devote 10 percent or more of their space to food. But it would have exempted stores such as Home Depot, which does not sell food, and club membership stores such as Costco.

Council President Steven A. Silverman (D-At Large) said the council revised the measure because it couldn't justify legislation that singled out stores that sold general merchandise and food, such as a supercenter, without evidence that such stores create traffic problems.

County Executive Douglas M. Duncan (D), a proponent of the zoning restrictions, has argued that "big box" stores would burden county streets with more traffic and take a long-term toll on the environment. Dozens of other governments, including Rockville and Alexandria, have passed restrictive zoning rules designed to slow the growth of big box stores.

Duncan's effort has won the support of the region's two biggest supermarkets, Giant Food LLC and Safeway Inc., and the union representing the supermarkets' 18,000 local workers, the United Food and Commercial Workers Local 400. The chains and their unions blamed tense negotiations over their latest labor contract on escalating competition from nonunion chains such as Wal-Mart, which typically operate at lower costs.

"We already have to jump through hoops to build a store," said Giant spokesman Barry F. Scher. "Stores that are two to three times the size of a typical Giant need additional attention from the regulators."

Wal-Mart is trying to assemble a coalition of big box stores opposed to the zoning restrictions to meet with members of the Montgomery Council. Masten said the coalition would target chains that operate stores bigger than 130,000 square feet, which could include Target Corp. and Home Depot Inc.

Wal-Mart is also asking shoppers in its two Montgomery County stores to sign a petition that called the proposed zoning rules "anti-competitive and anti-consumer." About 2,000 people have signed it, Masten said.

The chain paid DataUSA Inc. of Guilford, Conn., about $2,000 to survey 500 Montgomery County residents, asking if they opposed laws "meant specifically to stop Wal-Mart from ever building a supercenter in your county."

According to the results, 50 percent opposed the rule, 30 percent supported it and 18 percent said they were unsure. DataUSA performed the polls using questions submitted by Wal-Mart, said Executive Director Tracy Costin.

Ray McInerney, political director of the Metropolitan Washington Council of the AFL-CIO, said the poll is "full of holes" because it did not ask about the quality of Wal-Mart jobs and a supercenter's impact on quality of life in the county.

"If the company had bothered to do an in-depth poll," he said, "they would have found a very different picture."

Masten said the poll was designed to focus on the proposed ordinance. "We did not want to cloud the issue," she said. Masten sent copies of the poll to Duncan and council members.

McInerney said the union is preparing to counter the chain's lobbying bid. "We will make sure the council members and citizens are getting the rest of the story," he said.