Montgomery County Executive Charles W. Gilchrist followed through yesterday on a threat he had made to the County Council and vetoed a bill that could have limited building in the fast-growing county.

Describing the building limit as a "quick-fix approach in an election year," Gilchrist said the measure would have been "extremely disruptive" to businesses in the county. "It would not only affect a few developers," he said, "but thousands whose jobs are affected by the construction business."

The council agreed by a 4-to-3 vote last week to accept the limit, first proposed by council member David Scull, after nine months of debate over whether the county needed to limit growth.

The building limit was the last resort of a three-point proposal that first would have required the county to set up various methods of assessing development and establish a task force to monitor programs designed to alleviate traffic. If growth continued at its present pace, the cap would have gone into effect limiting the number of building permits for houses and commercial development to be issued during the next three years in congested sections of the upper parts of the county along I-270 and Rte. 29.

The building limit is one of several proposals recently reviewed by the council as possible answers to unprecedented growth and congestion.

Last week, the council agreed to institute a review of real estate and traffic trends by the council, county executive and County Planning Board.

Today, it is expected to decide whether the county needs to place extra "impact" fees on new development in crowded areas to provide those areas with needed services.

The impact fee, proposed by Gilchrist months ago and tentatively approved by the council two weeks ago, would be used to pay half the cost of new roads in the county. Gilchrist's staff had said earlier the fee could generate $6 million a year, but staff members said yesterday they were raising that projection.

If the council wants to override Gilchrist's veto on the building limit, five members would have to agree. That degree of consensus is not likely to occur, council members acknowledge.

Scull, a candidate for county executive, said yesterday that he considered Gilchrist's action to be "wrongheaded" and one "that will only make congestion worse."

In a news conference held to announce the veto, Gilchrist said there was "no way to administer evenly and fairly" the proposed limit and that it had been proposed "under election pressure."

"Some of the rhetoric and exaggeration used in the growth debate is political," said Gilchrist, who will retire from public office to become an Episcopal priest.