AUGUSTA — The Maine House today voted 90-59 to effectively repeal the Informed Growth Act, a law that was enacted just four years ago to protect Maine’s downtown business districts from the effects of big-box stores, such as Wal-Mart and Home Depot.

The vote, while a preliminary one, followed an impassioned debate about the character of Maine’s traditional downtowns and whether Wal-Mart and other large national retail chains have hurt local businesses or have helped them by attracting more people to communities.

Proponents of LD 322 said the Informed Growth Act discourages national companies from building their stores in Maine because the law adds costs and risks to the permitting process.

Moreover, they said that the big retail chains are popular. Rep. Lance Harvell, R-Farmington, said that Farmington residents used drive to Auburn to shop prior the arrival of Wal-Mart a few years ago.

By protecting existing businesses from competition, he said, the Informed Growth Act discourages new businesses and innovation. He said it would be like prohibiting Henry Ford in the 1920s from building an auto factory in town to protect wagon and harness manufacturers.

The Informed Growth Act’s supporters, however, said the law allows communities to examine the hidden costs of big-box development.

Rep. Seth Berry, D-Bowdoinham, said that repealing the law would make it easier for out-of-state corporations to build big-box stores that would hurt locally owned retailers located in traditional downtowns.

He pointed to downtown Brunswick. A few years ago, the town lost Grand City, a department store that had a soda fountain, because of competition from big box stores at Cooks Corner. He said other downtowns, such as Augusta and Biddeford, have suffered due to big-box stores built on highways at the edge of the cities.

The downtowns have suffered economically, he said, and as a result the “lifeblood and quality of life has unfortunately been sucked dry.”

The legislation would not eliminate the law outright. It would make it effective only in those communities that vote to opt-in.

As a result, cities and towns will be reluctant to opt-in because of the fear that they will be at a competitive disadvantage to neighboring communities, said Daphne Loring, coordinator for the Maine Fair Trade Campaign.

“We are concerned that communities will be punished for good planning,” she said.

The Informed Growth Act was enacted in 2007 after several midcoast Maine communities tried to block big-box stores from being built within their borders out of concerns that the big stores would drive local retailers out of business. Vermont is the only other state with a similar law, although it is less comprehensive. Some cities and regions have adopted similar measures.

It has been difficult to determine the law’s impact because of the lack of retail expansion during the recent economic downtown.

The act requires developers of projects of more than 75,000 square feet to pay $40,000 for an independent impact study that looks at 11 different possible impacts, including jobs, wages, municipal revenue and services.

The law requires the study to be presented at a public hearing. The local planning board then decides whether the project will have “an undue adverse impact” and, if so, cites at least two of the 11 factors that led to that conclusion. The planning board then must determine whether the overall negative impact is more than the positive impact and vote down the project if it is more negative.

The Senate has yet to take up the bill.