Gov. Harry Hughes' task force on drunk driving has recommended unanimously that the state's drinking age be raised from 18 to 21 to help reduce alcohol-related traffic accidents, the panel chairman says.

The task force, consisting of Maryland judges, politicians and private highway safety experts, voted last week to recommend that Hughes propose legislation to raise the drinking age to 21 when the General Assembly session opens in January.

Task force chairman William T.S. Bricker, director of the state Motor Vehicle Administration, said his panel backed the higher age after reviewing statistics from the Insurance Institute for Highway Safety showing that traffic fatalities decreased an average of 28 percent in nine states where the drinking age was raised from 18 to 20 or 21 years.

The drinking age in Maryland is 18 for beer and wine, 21 for hard liquor. The law is the same in the District. In Virginia, the drinking age is 19 to buy beer to carry out, 18 for beer consumed in restaurants and taverns and 21 for hard liquor.

Hughes so far has not taken a position on the touchy political issue that provoked one of liveliest debates in this year's legislative session. He is awaiting this week's formal recommendation from the task force to take a position, said spokesman Lou Panos.

But legislators heading two key committees of the House and Senate both predicted that election-year jitters and an increase in drunk-driving accidents could make 1982 legislators receptive to the pleas for a higher legal drinking age.

"It'll pass this year with no sweat," said Del. Joseph E. Owens (D-Montgomery), chairman of the House of Delegates Judiciary Committee, which backed the 21-year drinking age in the last legislative session. Owens is a member of the task force recommending the age increase.

"Our committee is predisposed to go to 21," said Sen. Joseph Curran (D-Baltimore). "I don't see anything wrong with keeping something that's harmful to people away from them a little longer."

The General Assembly, in a session marked by intense lobbying from tavern owners, debated a higher drinking age earlier this year. The proposal died when the House and Senate could not agree whether that higher age should be 19 or 21.

But even with talk of legislative harmony there were indications that debate could arise over whether the higher drinking age should be phased in exempting those who have already reached the lower drinking age of 18 or adopted across the board for everyone.

The last time the issue was debated, Hughes "had some misgivings" about raising the drinking age if the move would take away drinking rights from people already legally allowed to drink, Panos said.

The task force voted to recommend phasing in the higher age so that people now 18, 19 and 20 would not lose their right to drink. Curran said, however, he rejects that idea and called it "terribly cumbersome."