To accommodate a 300-acre life-sciences center in White Oak, Montgomery County Executive Isiah Leggett has proposed setting aside policies that require that new construction and transportation improvements go hand in hand

Leggett’s initiative, presented Wednesday, comes as the County Council deliberates over the White Oak Science Gateway Master Plan, a land-use blueprint designed to attract jobs and amenities to Montgomery’s economically neglected eastern sector. The plan’s centerpiece, a joint venture of the county and Percontee, a developer, would create a town center and hub for medical and life-sciences businesses near Route 29 and Industrial Parkway.

Officials envision an employment center that could generate as many as 10,000 jobs, spurred by the presence of the Food and Drug Administration headquarters nearby.

The council is scheduled to take final action on the plan July 29.

The development is one of the most ambitious revitalization undertakings in county history — 10 times the size of redeveloped downtown Silver Spring — with the potential for up to 25 million square feet of commercial space and 15,000 housing units. But the plan has triggered broad debate over its potential effect on an already overburdened road system, including the chronically congested Route 29.

The county usually requires some form of “staging” to align new construction with improvements to transportation and other infrastructure. At least part of the cost is borne by developers.

The council staff recommended, for example, that the science center be allowed to progress only if developers can show that a certain percentage of people will be traveling to the site by some means other than private cars (public transit, bicycles, on foot). Because the eastern county has suffered from a glut of housing and a shortage of jobs, the council staff also recommended that developers be limited to 2,000 residential units in the project’s first phase.

But the county government and Percontee, which own adjacent parts of the 300-acre site, are pressing the council to bypass the usual staging requirements. They contend that embedding too many requirements in the plan will make it more difficult to obtain favorable financing.

In a letter to council member Nancy Floreen (D-At Large), who chairs the council’s planning committee, Leggett (D) asked that the staging be scrapped.

“While these additional staging requirements may seem prudent, the practical implication of additional staging may jeopardize this opportunity for creating jobs and amenities in the East County,” Leggett wrote. He added that long-term transportation issues, including cost sharing between the county and the developer, will be worked out in an agreement to be drafted after the master plan is approved.

At Wednesday’s planning committee meeting, attended by most of the council, there was strong support for dropping staging requirements. Members said that the eastern county had been neglected for too long and that they needed to kick-start the White Oak plan.

“I believe we have a once-in-a-lifetime opportunity to move the East County forward,” Floreen said in a letter to colleagues, outlining her variation on Leggett’s proposal.

Council member George L. Leventhal (D-At Large) said it was imperative that any master plan include a commitment to finance bus rapid transit along Route 29, possibly by taxing area businesses.

“We need to send a clear statement to the public,” Leventhal said, adding that bus rapid transit is part of the region’s future.