Montgomery County's two dominant political parties came together yesterday in an unusual show of unity in support of a $150 million "Green Fields and Green Towns" initiative.

In the midst of a contentious election, chairmen of both the Republican and Democratic parties called a cease-fire on partisan politics to get behind the referendum, which would authorize spending to acquire open space, preserve farmland, and link trail ways and parks to older townships and boroughs.

The measure would surpass any single open-space initiative ever approved in Pennsylvania, according to Randy Gray, state director of the Nature Conservancy.

County voters will be asked to approve the initiative in the Nov. 4 general election. If it is approved, each municipality in the county would have access to between $590,000 and $3 million for projects in the short term, with another $83 million to be doled out over the next decade.

"We're hopeful that we can convince all of Montgomery County that this is a priority," said Republican Party chairman Frank Bartle.

The initiative is projected to cost $23 a year for the owner of house assessed at $160,000, the Montgomery County average.

Democratic Party chairman Marcel Groen said the investment in green space under a $100 million initiative in 1993 has saved the county money. He cited the plaza in Jenkintown, developed with open-space funds, that has served as a catalyst for downtown redevelopment there.

County committees for both parties have endorsed the initiative.

Thus far the only organized opposition to the initiative has come from the Libertarian Party, which is the county's third-largest party but makes up less than 0.6 percent of registered voters.

"The best way to preserve open space is through voluntary, private means," Jim Babb, chairman of the Montgomery County Libertarian Committee, said in a press release. "We can't let the politicians stick it to Montgomery County homeowners for this highly dubious, special-interest project."

Jim Seif, former secretary of the Pennsylvania Department of Environmental Protection, chairs the "Green Futures" political action committee, organized to campaign for the initiative.

Seif said that Montgomery County is leading the way to a new definition of infrastructure, where green space is as important as bricks and mortar.

"Space we don't do things with is also regarded as infrastructure," he said.