A controversial proposal to restrict chain stores in Sonoma has been significantly scaled back amid infighting among city leaders who are at odds over the issue.

The original proposal called for banning all "formula businesses" from Sonoma's historic Plaza and enacting new use permit requirements elsewhere in the city.

But the latest version, which is supported by a slim majority on the City Council, calls for banning only formula restaurants on the plaza. It also significantly shrinks the area where these businesses would be subject to use permit review.

The revisions to the draft ordinance were made at Monday night's City Council meeting following another testy exchange between council members on opposite sides of the debate, which was sparked last year with the opening of a Staples store at the site of a former car dealership.

Councilman Steve Barbose, who is the main proponent of new restrictions on formula stores, accused Mayor Joanne Sanders of being comfortable with a Starbucks opening on the plaza.

"That's not what our town is about," Barbose said.

But Sanders, who along with Councilman Tom Rouse is opposed to new restrictions, lamented what she said has been a lack of collaboration on the issue.

That brought a sharp retort from Barbose, who said his support for the revised ordinance was proof that he is willing to compromise.

"You need to acknowledge there has been some movement in that regard," Barbose said to Sanders, who did not respond to the comment.

Sonoma currently does not regulate chain stores other than through design review. Relatively few cities nationwide have more restrictive regulations, which some tout as a way to protect a community's charms and others view as an impediment to economic growth.

The debate in Sonoma centered initially on concerns that the city has little sway over a big-box retailer's plans to open in town. But now the focus appears to be on preventing a restaurant chain such as McDonald's or Starbucks from opening on the plaza.

"I think the plaza has always been the core of the issue," said Councilman Ken Brown, who along with Barbose and Councilwoman Laurie Gallian supports new restrictions.

The revisions made Monday night would ban restaurant chains with more than 250 outlets from opening on the plaza. Currently, the plaza is home to a Mary's Pizza Shack, which has 19 outlets, and a Ben & Jerry's, which has 580, according to their websites.

The plaza also has a Chico's, which has more than 600 outlets, and a Massage Envy, which has more than 700. But large-scale retailers would not be subject to a ban under the revised ordinance.

However, all formula businesses seeking to open at the plaza or in the city's historical district would have to get use permits under the proposed rules. A formula business would be defined as one with 10 or more outlets, excluding hotels, offices, financial institutions and other types of service businesses.

Williams-Sonoma, which has announced plans to open a store on Broadway where Chuck Williams founded the company in 1956, would be subject to the new use permit, which could add an additional two to three months to the planning process.

The original proposal, which was based on the recommendations of an ad-hoc committee spearheaded by Barbose, called for use permit requirements throughout the city.