SAN DIEGO -- Mayor Jerry Sanders vetoed an ordinance Friday that would ban so-called "big box" superstores within San Diego city limits.

Sanders said the ban, passed by the City Council earlier this month, limits the options available to consumers who want to save money.

At a news conference Friday afternoon, Sanders said consumers benefit from the savings Wal-Mart offers.

Many shoppers agreed, telling NBC 7/39 they enjoy the competitive prices as well as the convenience the chain offers them.

The mayor said consumers should be allowed to decide where to shop and how much money they want to save.

He also claimed the council was targeting Wal-Mart and offering loopholes to other big box stores.

The City Council has 30 days to override the mayor's veto.

If it does, Wal-Mart then has 30 days to collect 3,200 signatures and take the decision to the voters.

Meanwhile, in North County, two Wal-Mart stores have already been given the green light to expand.

The store in Vista will add 30,000 square feet to its store, and the other in Oceanside will be supersized next year.

Both projects were preapproved more than 10 years ago when the stores originally opened.