Environmental advocates and District activists called yesterday for a halt on proposed legislation that would allow the erection of two cellular phone towers in Rock Creek Park.

District leaders met with Robert G. Stanton, the director of the National Park Service, to voice their opposition to an amendment to the D.C. budget bill that would require the Park Service to allow Bell Atlantic Mobile, which wants to give its cellular phone customers uninterrupted service throughout the park, to build the towers at two spots in the southern part of the park.

The amendment, introduced by Sen. Thomas A. Daschle (D-S.D.), was passed by a voice vote in the Senate although the National Capital Planning Commission voted that same evening to table the proposal for a second time. The full bill, which was passed July 1, now goes to the House.

In a news conference before the meeting yesterday, leaders said the amendment bypassed the role of the regional planning board in setting policy for the park. "This is about open or closed government, honest or dishonest government," said D.C. Council member Phil Mendelson (D-At Large).

Del. Eleanor Holmes Norton (D-D.C.) said in an interview that she "was astonished and angered that Bell Atlantic, which has had a good relationship with my office, would go the Senate to use my appropriations bill in this way, with no notice to me." In his speech to the Senate, Daschle defended the amendment, citing the number of criminal and safety incidents in the park that may necessitate an emergency cell phone call and also the 1996 Telecommunications Act, which requires that federal land be made available to wireless services if they are needed and environmentally safe.

Norton said she is eager to broker negotiations to "try to find a way to accommodate all concerned before this becomes law."

Bob Posilkin, Bell Atlantic Mobile's real estate and zoning manager for the towers, said they are necessary to provide reliable service to customers traveling on the uneven paths in the southern half of the park.

Both sides have marshaled an array of experts for and against the towers. Posilkin said the towers comply with Federal Communications Commission standards on emissions and have passed an environmental impact study by the Park Service. Opponents believe the towers may emit electromagnetic radiation, the effects of which haven't been fully studied. Both sides also disagree on whether the towers would hurt migratory birds that fly through the park valley.

And while Bell Atlantic Mobile says the towers would be unobtrusive, opponents say the towers would be an eyesore, opening the way to scores of transmission antennas dotting the park's landscape. Under the plan, the towers would be placed at the edge of a park maintenance lot near Military Road and near the park's tennis center at 16th Street NW.

"Not one elected leader has spoken out in support of the Bell application," said James H. Jones, a member of the 4A Advisory Neighborhood Commission, who contends that the issue is more about home rule than about the towers. "We cannot allow a few in Congress to abridge the rights of the citizens of the District of Columbia."

Molly Rowley, a spokeswoman for Daschle, said: "Local zoning issues don't apply on federal land. . . . In the end, it's the federal government that's responsible for public safety on federal land."