Virginia Gov. Charles S. Robb proposed a freeze on state salaries and a $20 million cut in public school aid tonight to help close this year's projected $175 million budget gap without new taxes.

Robb, speaking before a joint session of the General Assembly and a statewide television audience, also called for raising the legal drinking age to 21 and urged postponement of a controversial coal slurry pipeline that has been proposed by the Virginia Electric & Power Co.

The governor's budget proposals, which are expected to dominate debate in the 46-day legislative session that began today, cut deeper and in more politically sensitive areas than his earlier actions to deal with a revenue crunch brought on by the recession.

Areas that were previously exempt--such as aid to local governments, education, and selected mental health programs--were hit in the new round of 6 percent, across-the-board cuts that Robb proposed. But major social programs, such as welfare and Medicaid, were once again spared.

Adoption of his program, Robb told the lawmakers, would spare Virginia the agony of higher taxes and drastically reduced services seen in other states.

"If you approve these actions, let me tell you what we won't have to do," said Robb. "We don't have to reduce the current salaries of any state employes. We won't have to shorten the work week. We won't have to contemplate general layoffs."

Robb's surprise call for a higher drinking age reflected the emotional concerns over drunk-driving fatalities here and a recognition that, for the 140 lawmakers facing reelection this fall, the issue is likely to become a hot political item of the session.

"Because most young adults have the maturity to deal with alcohol responsibly, I make this recommendation with reluctance," Robb said. "However, if we are serious about reducing the carnage caused by drunk drivers, I believe this course of action is necessary."

Robb added that he would not object to a "phased approach," similar to that adopted last year in Maryland. In Virginia, 18-year-olds can drink beer in restaurants and 19-year-olds can buy it at convenience stores. Twenty-one is already the legal age for purchases of hard liquor and wine.

Robb's comments about the coal slurry pipeline, the focus of a spirited lobbying battle between Vepco and the state's railroads, were equally unexpected. Robb, whose closest political adviser has been hired as a lobbyist by Vepco, said he did not necessarily oppose construction of the $650 million project, but that he "did not believe that we can responsibly resolve issues of this complexity" in the current session.

The governor also urged a one-year extension of the state's existing moratorium on uranium mining. However, the governor's expressed support for legislation recently recommended by the state's Coal and Energy Commission would lay the groundwork for such mining in the future and is therefore opposed by some environmentalists. See related story on the opening of the Virginia assembly, B7.

The speech received a generally warm reception from the Democratic-controlled legislature with lawmakers praising the usually cautious Robb for specific stands on tough issues. Republicans and some Democratic leaders warned that the education cut may not be approved.

"I think there is room for discussion," said House Majority Leader Thomas Moss (D-Norfolk). "Some cuts, particularly in education, will give some people some problems."

Republican leaders also accused Robb of overstating the state's fiscal problems. "Times are not as bad as some people would lead us to believe," said House Minority Leader Vincent F. Callahan (R-Fairfax). "Minor cuts in corrections, major cuts in education; I think the priorities are screwed up."

The unusual evening speech, hammered by Robb aides into the 24 minutes mandated by the half-dozen commercial and public television stations who broadcast it, was used by the Democratic governor to dramatize the severity of the state's fiscal problems and to expound before a state audience on his earlier actions to deal with them. Despite some bleak rhetoric, however, he was still able produce some new money for a few of his favored programs.

A state program to aid minority-owned and small businesses would receive a $100,000 increase, Robb said. He also proposed adding $500,000 to state spending on tourism, $500,000 for new state tax auditors and $160,000 in "seed" money for a nuclear accelerator in Newport News.

"Even in periods of austerity, however, which require difficult decisions there are investments state government can and should make . . . ," Robb said.

"Hard times offer no license to retreat from our commitment to equal opportunity and social justice for all Virginians," he said, expanding one of his favorite themes.

Of all the proposed budget cuts, the most difficult politically--although by no means the largest--was the proposed $20 million cut in state aid to public schools, a top priority of Robb's administration.

The cut would slash the proposed 10 percent increase in teachers' salaries that Robb recommended last year to 6.3 percent. That would dash his hopes of bringing Virginia's teacher salaries up to the national average. It would lower the minimum amount the state spends per pupil by $42 to $1,425, although the final figure is still $105 more than it was before Robb took office a year ago.

The governor also proposed taking $53 million for a state fund that helps finance school construction and using the money to close the budget gap.

Equally controversial is Robb's proposal to freeze salaries for 77,000 state employes, scrapping any step or merit increases that were scheduled for six out of 10 classified employes. Salaries for college employes and local constitutional officers would also be frozen for the next 18 months.

Local governments will feel the impact with cuts in various categories of state aid, satisfying those who have argued that state programs should not be only ones to suffer during the tough economic times.

Also contributing to this article were Washington Post staff writers Sandra G. Boodman and Fred Hiatt.