Five legislators vigorously invoked the causes of justice and taxpayers' rights today in trying to persuade a House of Delegates committee to grant $1,218,080 in tax breaks to their favorite special interest groups.

As a sparse auidence of lobbyists and their supporters looked on, the five delegates variously argued that Maryland's watermen, printing firms, school bus contractors, manufacturing firms and PTA organizations deserved to be exempted from paying the 5 percent sales tax imposed on most of the rest of the state.

In each case, they contended that the sale tax was unfair to their constituents or imposed an undue burden on an industry vital to the taxpayer's interests. Del. David B. Shapiro (D-Baltimore County) testified, for example, that giving state printing firms $267,422 in tax relief next year would increase the firms' business and thus help Maryland's economy.

The legislators freely admitted that they had more than simple justice at heart in proposing the tax breaks.

Del. Lewis Riley (R-Parsonburg) noted that he understood why the school bus contractors wanted $275,000 in tax relief because he had been a school bus contractor for 24 years in rural Wicomico County. Del. W. Henry Thomas, who proposed the $300,658 break for watermen at the urging of commerical fishermen's groups, lives in the Eastern Shore harbor town of Cambridge, where fishing is a major industry.

The most expensive of the five tax breaks was proposed by Del. DeCorsey Bolden, a Republican who represents the mining areas of Western Maryland, his bill would clip $341,000 from the taxes of firms that buy equipment for handling raw materials, pleasing a powerful lobbying interest.

Shapiro, in turn, noted that his printing firms bill was prompted by complaints from several printing firms that are located in his Baltimore district and the $34,000 tax break for PTA groups was proposed by Kay Bienen, a delegate from Prince George's County where education groups wield considerable political influence.

The delegates proposals were greeted with little surprise by members of the House Ways and Means Committee, who say that proposals for selective tax breaks annually are heard -- and killed -- by the dozen in their chambers.

More are scheduled for this session, in addition to the ones heard today. Tomorrow, for example, Del. Gerard Devlin (D-Prince George's), the vice chairman of the committee, plans to introduce a bill that would save vending machine merchants up to $1 million in sales taxes they now pay annually.

Devlin says that the various measures are part of a bit-by-bit process through which the legislature is dismantling those taxes that are considered outmoded of politically unpopular. "We're nibbling away at the sales tax system," he says. "But you have to look at it over a period of years to see how it happened."

At the same time, Devlin and other committee members said that the sales tax exemptions proposed yesterday have little chances for passage this year. "What we're faced with," Devlin said, "are dozens of little good causes that cost a lot but don't bring much tax relief to a lot of citizens."

The Ways and Means Committee also held hearings today on seven other proposals for sales tax exemptions directed largely at consumers.

The biggest of these tax breaks was proposed by Dels. William McCaffrey and Anthony Cicoria of Prince George's and would exempt carry-out foods sold at supermarkets, delicatessens, and other fast-food outlets from the sales tax at a cost of $15 million to the state.

Two other measures would grant close to $7 million in sales tax exemptions to citizens who purchase energy-saving devices for their homes or buy alternative fuels such as wood.

The committee will meet to vote on the bills within the next two weeks, members said.