A reluctant Maryland Senate gave final approval today to a bill to raise the state's legal drinking age to 21, with many senators who voted for the measure conceding that they were doing so because of intense public pressure in an election year.

An identical bill previously passed the House of Delegates. As soon as one side accepts the other's bill, which one senator termed "a formality," the measure will go to Gov. Harry Hughes for his signature. Hughes was a principal backer of the higher drinking age and personally lobbied recalcitrant senators for today's vote.

"It's going to save lives," said Sen. Francis X. Kelly (D-Baltimore County), who was one of the senators who gave unqualified support to the legislation. "It's not going to solve the problem, but it will improve the situation--the drinking-driving, the teen-agers with alcoholism problems."

Today's vote capped one of the legislature's longest-running debates, which began soon after the age was lowered from 21 to 18 in 1974. With an increase in alcohol-related traffic fatalities among the young and complaints from school administrators about alcohol in the schools, most legislators had agreed for some time that the age should be raised. But each year the decision was blocked by stalemates between the House and Senate.

But the lopsided 35-to-10 margin by which the bill passed today blurred the sentiment of many senators who said they favored leaving the drinking age alone or raising it to 19.

Caught between representing what they perceived as their constituents' views or voting their consciences--a dilemma epitomized in political theory 200 years ago by British parliamentarian Edmund Burke--Maryland senators opted to go with "the people," at least in an election year.

"I have no choice," declared Sen. Victor Cushwa (D-Washington County). Cushwa voted for 21 only minutes after warningthat the higher drinking age would create "suicide alleys" on the highways leading from his Western Maryland county into neighboring West Virginia, where the drinking age remains 18.

Sen. Clarence W. Blount (D-Baltimore) voted for 21 but said, "I am not happy with myself for doing it."

"I am voting the way I feel the people want me to vote," said Sen. Verda F. Welcome (D-Baltimore).

Sen. Arthur Dorman (D-Prince George's), summing up the view of many senators who originally favored raising the age to 19, said he was casting "a sorrowful vote for 21," because, "this is the only game in town."

Other senators scolded their balking colleagues for casting votes they did not believe in, and challenged their apparent lack of intestinal fortitude.

Sen. Clarence Mitchell (D-Baltimore), who voted against the bill, scanned the 35 green "yes" votes on the electric tally board and compared some of his colleagues to "three blind mice. . . . When you see all those green lights up there, you realize how we run."

"Everybody stands up on the floor and says they don't want 21," sniped Sen. Tommie Broadwater (D-Prince George's), a tavern owner who voted against the bill. "If you don't want 21, don't vote for it."

Sen. James C. Simpson (D-Charles County) called the higher drinking age "an editorial bill from the Baltimore Sun and The Washington Post." Simpson did not vote because of his own liquor-related business.