Maryland Senate President Melvin A. Steinberg, piqued by a labor lobbyist's request for a private meeting while the Senate was in session, lambasted the legion of lobbyists here tonight as a threat to the General Assembly's "integrity and objectivity."

Steinberg's harsh remarks came moments after he received a handwritten note on the business card of Edward R. Lamon, the veteran lobbyist for the Maryland State & D.C. AFL-CIO. Lamon, who represents 400,000 union members in Maryland, had sent the note into the Senate chamber, asking Steinberg to meet him outside to discuss a possible compromise over controversial workers compensation legislation.

Steinberg, irritated that he was being asked to leave the president's rostrum during Senate business, launched into a 15-minute diatribe against all lobbyists, whose work is reaching a fever pitch in the final days of the legislative session.

"I'm concerned about the whole atmosphere down in Annapolis . . . being interfered with by a lot of commercial lobbyists," Steinberg declared. "Collectively, politicians are perceived as being a little above used-car salesmen," Steinberg said. But, he added, "no outside force is going to destroy the integrity of this body."

"I'm not about to allow this body to be directed by the Chamber of Commerce or organized labor," said Steinberg, a Baltimore County Democrat who used to be a labor negotiator.

The allusion to the statewide business organization and Lamon's group was an apparent reference to an acrimonious debate in the Senate earlier today on the workers compensation bills.

One measure, already passed by the House of Delegates, enjoys the favor of labor because it would equalize insurance premiums paid by union and nonunion shops. The other, which originated in the Senate, would limit certain employe disability benefits and has been embraced by business groups.

The Senate was deeply divided over the measures on workers compensation, which like many issues in the final four days of the 1986 General Assembly are the focus of intense lobbying.

"I'm not naive to politics -- that's the game," Steinberg told reporters later. "It's just progressively getting worse, the number of lobbyists that are being retained."

Lamon said he was perplexed by Steinberg's speech. "I don't know what his point was," Lamon said. "The lobbyists have a right to lobby -- it's part of the process of government and a constitutional right." Nor did he regret sending in a note to attract Steinberg's attention, Lamon added. After all, he said, "The Chamber of Commerce sends their cards in all the time."