The Maryland Senate, with surprising ease, gave preliminary approval to Gov. Harry Hughes' proposal to create a new, cabinet-level labor department.

The 31-to-10 vote for the new department, desired by union leaders and disliked by business representatives, was a significant victory for Hughes, who just a few weeks ago faced seemingly insurmountable opposition to what he called the centerpiece of his 1983 legislative package.

Today's vote was considered the toughest test of legislative support for the measure and indicates that when the session ends in two weeks, Maryland is likely to have 13 cabinet departments instead of the current 12. Final approval by the Senate is scheduled for later this week, and House consideration will come after that.

The department will cost some $500,000 to set up, and it will have jurisdiction over a variety of jobs and unemployment programs, including the dispensation of unemployment benefits, that currently are in other departments. It also will pick up some 1,500 workers from other agencies.

Hughes' victory followed weeks of intense lobbying by the governor with a majority of the 47 senators. It also came just days after the seven Prince George's County senators, told by Hughes of his support for a lottery bill considered vital to county interests, agreed to drop their opposition to the labor legislation.

"I think the sentiment was always there," said Hughes' legislative lobbyist John F. X. O'Brien.

Many members of the legislature had attacked Hughes' proposal as a campaign promise made last fall to curry favor with politically powerful labor unions.

Major unions withheld endorsements in the gubernatorial campaign until after the primary--and after Hughes announced the proposed new Department of Labor, Employment and Training. Hughes and his aides said the timing of the announcement of the proposed department was coincidental and that the department had been in the works for a year.

The department's name was changed by the Senate to leave out the word "labor" at the urging of business leaders.

Hughes' lobbying did not diminish the strong rhetoric against the bill when it came up for consideration today. "This has become the governor's macho means for showing his strength (and) fulfilling an election-year promise," said Sen. Julian L. Lapides (D-Baltimore).

"Today's crisis is training and retraining the unemployed," said Senate Minority Leader John A. Cade (R-Anne Arundel). "We don't need a department that will spend six months deciding where it is going to live, what color its rugs and drapes will be, who's going to sit where. What we need is a marshalling of forces now, and there are lots of ways to do it other than setting up a new department with a half-million in taxpayers' money."