BOSTON--The Massachusetts House, brushing aside Republican attempts to stall debate on Gov. Michael S. Dukakis' universal health care bill, gave initial approval last night to the proposal, which is the first of its kind in the nation.

The Democratic-controlled House endorsed the measure by a 99-53 vote after rejecting an amendment that would have removed the heart of the bill--a requirement for most employers to offer health insurance to their workers by 1992.

House Minority Leader Steven D. Pierce (R.-Hampden) introduced the amendment to drop the mandate, saying small business opposed the requirement despite a provision in the bill exempting firms with six employees or less.

Small businesses were opposed "not because they don't believe that health coverage is important to the people who work for them," Pierce said, "but because they believe they should have the right...to work out that choice based on [their] fiscal constraints."

But when House Ways and Means chairman Richard Voke (D.-Chelsea) rose to speak, the stage was set for the critical vote. "This is the whole enchilada," he said. "If you take [the mandate] out, this is it."

The House's Democratic majority responded, defeating the amendment 86-66. Immediately afterward, the House tentatively endorsed the whole bill 99-53. Another vote will be needed in the House, which meets in formal session today, before the measure can move to the Senate.

Passage in the House, which scuttled Dukakis' health care bill in the 1987 session, is the key hurdle for the measure. Late in the 1987 session the Senate passed a bill similar to the one now before the House.

Earlier in the day, Republican State Committee Chairman Ray Shamie and Dukakis exchanged broadsides over the swift schedule the Democratic leadership had plotted for the bill's consideration.

But House Speaker George Keverian (D.-Everett) quelled calls for postponement when he took the podium for a rare floor speech and announced, "I want this bill to pass. I want this week to be one we remember as long as we live--one in which we faced the challenge and won."

Shamie charged before the debate began that the Democratic leadership had put the bill on a fast track to help Dukakis' presidential campaign.

"No one knows how much this bill will cost," Shamie told a news conference. "But Mike Dukakis knows it will help his presidential campaign."

Republicans contend House leaders want to pass the bill in time to give Dukakis a boost for the "Super Tuesday" presidential caucuses and primaries in 20 states next week.

Shamie said more time was needed to study the bill. If that time wasn't granted, the Republicans threatened to run radio ads before the November election claiming, "The Legislature rammed the bill through so Mike Dukakis would have something to crow about in his quest for the White House."

"I don't know that the Republican Party in this state has had a constructive idea in years, and this is another example of it," Dukakis fired back when asked about Shamie's comments. "It's one of the reasons why the Republican Party in this state is in such terrible shape."

Dukakis said it was immaterial whether the bill passed before Super Tuesday. "I have no particular interest in whether or not this bill does or doesn't make it to my desk in the next week," he said, adding his only concern is getting "the best possible bill."