Last week, Alexandria Vice Mayor Margaret B. Inman surprised her fellow Republicans by announcing that she was giving up her office for the man she loves.

This week, as Inman relaxed on Bermuda's beaches with her new husband, Republicans in Alexandria talked anxiously of their desire to keep Inman's seat in the Grand Old Party. Democrats said they see the resignation as an opportunity to end the GOP's recent surge in Alexandria politics.

Democrats hold four of the seven council seats. That narrow majority, however, was won by only 200 votes in the May 1985 election.

While many say the Republicans are likely to win Inman's seat because of the strong showing the GOP had in the last election, most agree that Inman's announcement hurts the party.

As the top vote-getter in the 1985 elections, winning 2,000 more than Mayor James P. Moran Jr., Inman was viewed as a potentially strong mayoral candidate for 1988.

She could have won the city's top elected post for her party for the first time in more than a century, her supporters said, and spurred the Republicans on to their first majority in Alexandria since Reconstruction.

Inman, 59, announced last week that she would leave the seat she has held since 1979 to marry Alexander B. Clarke, a retired officer of Sohio Petroleum Co.

Inman's father, a Methodist minister, married the couple Saturday in a ceremony at Inman's daughter's home in Cleveland.

The couple plans to live in Alexandria briefly and then move to Clarke's home in Clover, S.C.

While undecided as to when she will make her resignation formal, the vice mayor is expected to time her departure so that the council race will coincide with the November general election.

According to Virginia law, the special council election can be held at the same time as the congressional election if she resigns within 90 days of Nov. 4.

Alexandria Democratic Party Chairwoman Jo Ann Miller said her party will use the election as a chance to increase its strength on the council.

In 1985, the party lost two of its strongest vote-getters, five-term mayor Charles E. Beatley and nine-year council member Donald C. Casey.

"We'll find somebody to run . . . we're ready to use this chance," Miller said.

Moran, who is not considered as partisan as Beatley, challenged him as an independent in 1985, and Democratic newcomer Redella Pepper filled Casey's seat.

If Casey -- who was one of the most outspoken members of the council -- decides to run this fall, as he says he may, he will undoubtedly liven up the race.

A relentless critic of Police Chief Charles S. Strobel, Casey's reappearance on the political circuit should churn anew the animosities surrounding the Strobel controversy.

Strobel was investigated by a special state grand jury last year and later indicted by a federal grand jury on charges of perjury and obstruction of justice.

He was cleared of all charges, but only after pitting some city officials who supported him against those who opposed him.

Another Democratic contender mentioned is School Board member Lynnwood G. Campbell Jr., who last year finished 11th, behind Casey, in a field of 14.

The Republican candidates mentioned include William C. Cleveland, a member of the Capitol Police who came within 200 votes of defeating council member Lionel Hope; real estate broker Gus Lamond, and West End resident Anne Moore, who was defeated in a heated and costly campaign last year against Del. Bernard S. Cohen (D-Alexandria).

John D. Williams, president of the Alexandria Taxpayers Alliance, who last year ran unsuccessfully for mayor as an independent candidate, is the only announced candidate so far.

As for Inman, she is expected to return from her honeymoon to attend the Tuesday council meeting.

She answered quickly when asked how she could give up a political career at its height. "Mr. Clarke made me a better offer," she said.