A Walmart in Hyattsville, Md. (Jonathan Newton/The Washington Post)

Prince George’s County Council members voted Tuesday to block Walmart’s proposed expansion of a store in Landover Hills, reversing a decision by the county Planning Board that had sparked an outcry from community activists.

Council member Dannielle M. Glaros (D-Riverdale Park), in whose district the Walmart is located, said the 35,200-square-foot extension was too large to be approved by county planning officials and should have undergone a more thorough screening.

A day after a public hearing was held on the matter, Glaros made a motion to reject the Planning Board’s approval, and council members — who act as the District Council on land-use matters — voted unanimously in favor.

Walmart can appeal the council’s decision in court or pursue expansion approval through the county’s special-exception process — a more rigorous zoning review that allows regulators to more closely examine the project details and creates more opportunity for public input.

Neighborhood and community activists have long complained about security and conditions in and around the big-box store in the 6200 block of Annapolis Road.

Prince George’s County Council member Dannielle M. Glaros (D-Riverdale Park) (Courtesy of Danielle Glaros's campaign)

They said that, although Walmart promised to help spur additional development around the store when it sought to open there 10 years ago, new retail offerings have been sparse, and some well-regarded stores have shut down.

Walmart said its efforts were slowed by the Great Recession and pointed out that some new stores are coming. It said the proposed expansion would make possible a much fuller grocery section to help make up for the departure of a Safeway.

Denise Hamler, who leads a coalition of organizations dedicated to upholding the decade-old agreement between the community and Walmart, said she was “thrilled” at the council’s action.

“We have been working on this for years,” Hamler said. “We cannot support an expansion until they respond to our issues with the current store.”

But Walmart spokesman Phillip Keene said in a statement Tuesday evening that “there is a lot to like about our plan and, most importantly, our customers have told us they want the improvements.

“We were ready to invest in the store and the community, so we’re pretty disappointed in today’s decision,’’ Keene said. “At this time, we are reviewing our options in terms of next steps.”