In addition to navigating a lengthy approval process, developers of a proposed CVS pharmacy have a new obstacle – opposition from organized residents.

Calling themselves “The Citizens Committee to Oppose CVS at the Gateway to Marion,” the group of 20 launched a petition to gather the signatures of 1,000 people who are against the project.

The petition, available online at Change.org, declares that “Development of a generic 'big box' retailer such as CVS would be detrimental to the character of our beloved community, and contrary to the intent of the town’s bylaws.”

So far, 149 people have signed.

“Our committee is focused on the adverse effects a CVS would have at that particular site,” said committee member Judy Rosbe. “We’re against having a CVS built on that site. We’re not against CVS building in town.”

In September, Mark Investments LLC unveiled plans to construct a 14,600-square-foot pharmacy and store with a drive-thru at the intersection of Route 6 and Front Street.

To accommodate the store, the 3,900-square-foot historic Captain Hadley House would be moved to an adjacent lot.

Rosbe, a member of the Sippican Historical Society’s board of directors, said the plan would alter the town’s historic fabric.

“Of course, the Historical Society is interested in not seeing the Captain Hadley House moved,” she said.

Committee members noted a vacant lot at the Route 6 and Point Road intersection provided the project enough space, without relocating a historic building.

In October, Mark Investments met again with the Planning Board after they changed the initial blueprints.

Instead of a blocky pharmacy, new plans incorporated historic elements, such as dormers, white cedar shingles and cottage-style windows. However, the building’s size remained the same.

That meeting, held in the Music Hall, attracted a standing-room only crowd.

Another meeting between the Planning Board and Mark Investments is set for Monday, Dec. 15 at 7 p.m. in the Music Hall.

“This is a critical turning point,” said committee member Tinker Saltonstall. “The applicants have not formerly applied yet and are still meeting with various boards.”

Saltonstall said a grassroots effort on Nantucket inspired the group to launch the petition. In 2012, CVS withdrew plans to open a store on the island.

Using the online petition site Change.org, Nantucket residents gathered more than 4,000 signatures.

Saltonstall said her committee hopes a similar drive will cause developers to rethink the store’s location.

“We will be sending the petition to CVS corporate,” Saltonstall said. “Hopefully, that will influence their thinking.”

The group also has a Facebook page titled “Stop CVS at Marion’s Historic Entrance” where news, updates and more information is posted.

Saltonstall said the committee is aware that convincing developers to relocate is the start of a “long battle.”

Her husband, Bill, another committee member, added that if developers insist on building on Front Street he’s confident town bylaws can block the project.

“The Planning Board should have the right to turn it down,” he said. “We need to plan smart and let people that want to build in Marion know what the rules are.”