Montgomery County Executive Charles W. Gilchrist, stepping into the thick of a bitter race among his would-be successors, yesterday accused candidate David L. Scull of using "mudslinging" and "name-calling" to fight proposed changes in the county's land use planning laws.

The normally reserved Gilchrist employed unusually harsh language against Scull, a Democratic County Council member and frequent political rival, to defend his administration's proposals to strip the council of two cherished powers in Montgomery's land use planning process.

Gilchrist's proposals, which grew out of a special commission report last year on Montgomery's severe growth problems, would give future county executives new powers to appoint two planning board members and veto land use master plans. Members of Montgomery's legislative delegation in Annapolis have endorsed the proposals, saying they agree with Gilchrist's contention that the changes are needed if the county government is to get a handle on the suburb's growth.

Scull, who is running for county executive against state Sen. Sidney Kramer (D-Montgomery) and county Recreation Director David Robbins, has castigated Gilchrist's proposals, describing them as part of a campaign by local developers to "capture" the county executive office by contributing heavily to Kramer's campaign. Kramer, who has been endorsed by Gilchrist, was a key supporter of the executive's proposals in Annapolis.

Yesterday, in a speech before the Montgomery County Press Association, Gilchrist responded to Scull's recent criticism by saying, "According to council member Scull . . . five of our seven state senators and 12 of our 21 delegates were in a conspiracy.

"If these are the co-conspirators, I am flattered to be included in their numbers," said Gilchrist. "The voters of this county will render a harsh judgment against that kind of mudslinging."

Scull, informed of Gilchrist's remarks, dismissed the criticisms and said he will continue to oppose the proposals to change the planning law.

Gilchrist sharply criticized Scull's suggestion that government sharply limit future growth by placing caps on development.

"During Mr. Scull's time on the council, he voted for every zoning application that came before him and even opposed the staging plan which my office recommended for the Washingtonian tract," said Gilchrist, alluding to a massive development that is planned for the already congested Rockville-Gaithersburg area.

"Now, suddenly, this man who blindly voted for all the zoning would have the people of the county believe that they must put a stick in the spokes of our economy to avert the evils of the last decade."

Scull called the executive's speech "an effort to prop up Sen. Kramer's faltering campaign . . . which is the captive of special interest campaign money, primarily from the development industry."

Kramer filed a report with the state in the fall showing that nearly 70 percent of the $126,000 he had raised for the race had come from developers and related companies.

Gilchrist's remarks about Scull -- and a spirited plug he gave Kramer during a question-and-answer period yesterday -- mark the first time the executive has jumped forcefully into the Scull-Kramer battle.

And his speech reflected a discontent among Montgomery politicians about the course of debate over the county's future growth, a public discussion that some say is increasingly caught up in election year politics.

"What thwarts constructive debate and action is name-calling and threats of political reprisal based on accusations of villainy," said Gilchrist. "We must not change a debate into a melodrama where the public is really the victim."