City leaders in Gaithersburg and Rockville are demanding county officials correct "fundamental" failings in the multi-decade vision for building an 800-acre Science City between the cities' borders.

Gaithersburg's mayor and city council unanimously approved a resolution Monday night saying the County Council must re-examine more than a dozen aspects of the Gaithersburg West master plan, the county's broad-strokes blueprint for tripling the Shady Grove Life Sciences Center to 20 million square feet of commercial space, roughly 9,000 homes and capacity for more than 40,000 jobs.

Rockville expects to finalize its nearly identical resolution tonight.

Echoing the growing outcry from neighbors and civic activists, leaders from both cities have stressed they whole-heartedly endorse the effort to enhance the county's biotech presence, but say Gaithersburg West has not adequately accounted for the degree to which it will overwhelm communities and infrastructure within municipal borders.

The measures come a week after the city councils and most of the County Council discussed Gaithersburg West at a roundtable meeting.

The resolutions claim county leaders have "failed or refused to take action" on concerns with Gaithersburg West's traffic studies; affordable housing levels; strategies to mitigate community impacts; requirements to stagger construction into stages marked by specific infrastructural milestones; connectivity of pedestrian, parkland and open-space networks; and plans for coordinating development with Gaithersburg and Rockville over the decades to come.

If the County Council cannot address those concerns, Gaithersburg and Rockville say the plan must go back to the County Planning Board.

While the resolutions carry no legal weight, city leaders are calculating the Gaithersburg West debate has become so heated that failing to address the concerns could bring a heavy cost to bear. "The consequences are political," Gaithersburg councilman Ryan Spiegel said.

"I don't think the County Council wants to be perceived on something as important and consequential as this decision as having railroaded Gaithersburg and Rockville," Gaithersburg councilman Jud Ashman said. "... We've approached the whole process in good faith, with the expectation that we would not be ignored. And now that we see that they're talking about putting an end to the process, now is the time to speak up more strongly."

On Tuesday, county leaders said they saw no need to deviate from the council's review. With Gaithersburg West still in committee through March 22, the full council is not expected to wrap up its review until mid-April.

"It's like any group that has a valid point of view; we respect it and we look into it," said Council President Nancy M. Floreen (D-At large) of Garrett Park.

Since the planning board's July draft, county officials have adjusted several of Gaithersburg West's sticking points — for example, the county now says it does not need an interchange at Great Seneca Highway and Key West Avenue, one of six proposed grade-separated interchanges.

County Executive Isiah Leggett has been an adamant supporter of the vision while trying to acknowledge the impact the massive project will have on surrounding communities. In September, he recommended the amount of commercial space be pared back to 18 million square feet.

"This is a critically important project, and if we're interested in making sure we move biotech jobs to a higher level, we think that the Gaithersburg West master plan makes perfect sense," county spokesman Patrick K. Lacefield said.

Debate over Gaithersburg West began in earnest more than two years ago, spurred in large part by Johns Hopkins University's plans to build an academic and research campus at the 107-acre Belward off Muddy Branch and Darnestown roads.

Neighbors' angst mounted as the plan went through Planning Board deliberations ahead of its July draft and reaching a head in October, when more than 80 people testified at the County Council's public hearings on Gaithersburg West, a record turnout for a master plan.

Last week, Hopkins officials offered the first public glimpse of what Belward would look like as an academic and research campus for 15,000 students and scientists. That concept strays from the glass-and-steel style more typical of research architecture for two reasons: to follow suit with the university's Baltimore campus, and to better fit with Belward's residential surroundings, said David McDonough, senior director of development oversight for Johns Hopkins Real Estate.

But the drawings present an "idyllic" look not in tune with the everyday reality neighbors will have to face.

"This is what it's going to look like on a Sunday afternoon. It does not show the thousands of cars that are going to be trying to get in and out of that place," said Lynn Rose, a resident of Mission Hills and member of Residents for Reasonable Development, one of two civic groups opposed to Gaithersburg West's full build-out.

Correction: Rockville finalized its resolution Tuesday night.