Santa Clara has filed suit against San Jose over a large office development near Santana Row, firing the latest salvo in a bitter turf war that has developed between the two Silicon Valley cities.

San Jose took the first swing four months ago when it sued its neighbor to the west over Santa Clara’s CityPlace, a massive $6.5 billion office and retail development near Levi’s Stadium.

Now, Santa Clara has gone to court over San Jose’s big Santana West project for office space and more retail on Santa Clara’s southern border.

“San Jose has forced us to do this,” Santa Clara Mayor Lisa Gillmor said Monday. “It’s a bad precedent when you start questioning what other communities are doing, but apparently, it’s now necessary. I didn’t want to go down this path, but now we have to make sure we’re advocating for our residents.”

San Jose City Attorney Rick Doyle called Santa Clara’s lawsuit frivolous, spiteful and thin on facts.

“This is in retaliation for our lawsuit,” Doyle said. “Mayor Gillmor made it clear they were going to look at San Jose, and this lawsuit is purely out of spite. All you have to do is read the complaint and you can see there’s nothing to it.”

Gillmor said Santa Clara is scrutinizing other San Jose projects near its border but “doesn’t know” if more lawsuits will follow.

Santa Clara on Friday sued San Jose over Federal Realty’s 970,000 square-foot office development near Santana Row. The San Jose City Council on Oct. 4 approved the project’s environmental impact report, a critical step in moving it forward.

Santana West calls for 29,000 square feet of retail, with six new buildings replacing the Century 22 and 23 theaters on Winchester Boulevard. The nearby Century 21 was declared a historic landmark in 2014, but San Jose leaders last month gave the developer flexibility in reusing it — even stripping it down to its metal frames.

In its lawsuit filed in Santa Clara County Superior Court, Santa Clara accuses San Jose of violating the California Environmental Quality Act — the same claim San Jose made when it sued over Santa Clara’s CityPlace project. Santa Clara contends San Jose didn’t adequately study the “adverse environmental effects” that Santana West project will create or come up with a plan to reduce those impacts.

“It’s nearly a million square feet of pure office right on our borders, and that’s a horrendous intersection,” Gillmor said.

But San Jose Councilman Chappie Jones, whose district includes the project, said Federal Realty is spending $5 million for transportation improvements and has agreed to a plan to encourage alternative transportation.

“They are going to reduce the demand for vehicle trips,” Jones said. “They’ve gone above and beyond to try to mitigate any impact of the project.”

It’s not uncommon for opponents of a project to use the state environmental law to halt new development in a neighbor’s backyard.

San Jose filed suit in July to stop Related Companies’ CityPlace project in Santa Clara, which calls for 5.7 million square feet of office space and 1.1 million square feet of retail.

Santa Clara says the project would create an estimated 25,000 new jobs, but the city has housing for just 13 percent of the new workers. San Jose leaders, including Mayor Sam Liccardo, said they worried about increased traffic congestion and demand for housing new employees in a city that already has far more jobs than homes for workers.

But Silicon Valley political consultant Rich Robinson says it’s not about the impact of the projects on either city — it’s about politics. Santa Clara’s lawsuit appears to be payback for San Jose’s push to stop CityPlace, which would generate an estimated $17 million in revenue for Santa Clara a year, he said.

The fallout from the growing turf war could threaten the developers’ ability to secure funding, Doyle said, potentially delaying both projects. The lawsuits also could encourage abuse of the state’s environmental law, Robinson added — with taxpayers left picking up the tab.

“They’re only emboldening other people to use CEQA to bludgeon a project,” he said. “Delay is denial. If you can delay a project long enough, you can deny it.”