Montgomery County executive candidates Sidney Kramer and David Scull, embarking on a bitter Democratic primary fight, attacked each other yesterday as being unfit to handle the pressures of the county's record pace of development.

In separate news conferences, Scull and Kramer lambasted each other with language so vitrolic it marked the first real collision of their campaigns.

It also indicated that growth -- residential and commercial construction that generates tax money for the county but burdens commuters with traffic-clogged roads and students with overcrowded classrooms -- will be the main focus of the campaign.

The candidates' exchange came on the eve of a hearing before the County Council today in Rockville at which several proposals to limit growth, including one to reduce some development by as much as 40 percent, will be reviewed. The event has drawn 65 speakers, including a spokeswoman for Kramer; his political ally, County Executive Charles W. Gilchrist, and a waiting list of 30 other witnesses.

Kramer, a state senator who served on the County Council in the 1970s, called Scull a liar, employing a common expletive, in conversation with a reporter after a morning news conference at his Silver Spring headquarters.

At the news conference, Kramer said Scull was unsuited to the executive's job because of his years in the "politics of polarization" on the strife-torn County Council.

He also cited a recent newspaper survey of council voting records that showed Scull joined the council majority in voting for 136 of 140 land rezonings since 1981, and called this a "sorry record on the issue of growth."

Kramer defended the many large contributions that his campaign has received from local developers, saying he would "make no apologies for accepting those funds."

"They're totally disclosed and totally legal," he said.

Three hours later, meeting with several of the same reporters at his Chevy Chase law office, Scull, too, stepped up his rhetoric, saying Kramer had engaged in a "special-interest extravaganza," managing a "flood" of large contributions by developers, real estate industry members and their families.

Scull, who has declined to disclose what money he has raised toward his $200,000 goal, said he would restrict sharply the number and size of contributions he would accept from developers. Late last year, Kramer reported raising about $125,000 for the race, of which $85,000 was from developers or local business persons.

Scull, as he has in the past, attempted to portray Kramer as a tool of the business community, suggesting that Kramer the county executive could not be impartial in his dealings with developers.

"Almost all of Sen. Kramer's money is from the development industry," said Scull.

He called Kramer an "advocate" of special interests and said sizable donations by industry representatives might make Kramer "vulnerable to their influence."

Scull, who has dominated a year-long County Council debate over how best to manage development, renewed his call for a controversial cap on building permits and excise taxes on new construction projects. Both ideas are anathema to Gilchrist and the local building industry, which recently took out full-page advertisements in some newspapers to counter the proposals.

"I am in favor of quality development balanced against the quality of life in the county -- and I always have been," said Scull.

Kramer, who has proposed a few alternatives to Scull's overall plan on new growth restrictions, echoed Gilchrist's call for lower "impact" fees, which builders would have to pay before obtaining permits for construction along the congested north-south arteries of Interstate 270 and Rte. 29.

For months, Kramer remained largely silent as Scull made political hay by needling him over his close ties to business. At his news conference yesterday, Kramer struck back.

"I will no longer tolerate his personal attacks on my integrity," said Kramer. "No one can expect any special favor . . . because they have given me a campaign contribution."

The Scull-Kramer warfare drew rueful commentary from David Robbins, the county recreation director who is the third candidate in the September Democratic primary.

"This is name-calling press conference-type of campaigning," said Robbins. "The voters are going to repudiate candidates who insist on staying on the low road."

Republicans Albert Ceccone and Edward Gannon are competing for their party's nomination in the September GOP primary. Today's public hearing on ways to control growth is set to begin at 1:30 p.m. on the third floor of the County Council office building, 100 Maryland Ave., Rockville.