Gov. Harry Hughes' proposal to set up a cabinet-level labor department ran into opposition at its first hearing today as skeptical legislators intimated that one reason for creating it was to appease politically powerful labor interests.

The coolness displayed by home members of a House Appropriations subcommittee may be indicative of what legislative leaders said will be a tough fight to win passage of the new Department of Labor, Employment and Training. Opponents said the department may not be necessary and would add another layer of expensive bureaucracy to state government.

Hughes' staff members, who have been conducting a quiet but intensive lobbying effort with advocacy groups, industry and legislative leaders on behalf of the proposal, admit it faces hurdles in the legislature, but said those can be overcome.

The Labor Department, as it is being called, much to the chagrin of the state's business community, was proposed by Hughes during his reelection campaign, at a time when some unions were expressing dissatisfaction with his administration and had withheld an important Democratic primary endorsement.

Hughes contended that the idea for the department had been under consideration for months, as a way to consolidate state efforts on employment and to retrain displaced workers for jobs in high technology fields.

The governor also has said the new department, which initially did not have the word "labor" in its title, is vitally needed to implement the new federal Jobs Partnership Training Act. Under the act, the state will receive at least $44 million, and possibly as much as $58 million, for employment and job retraining programs.

Jim Callahan, director of the training and employment division of the Department of Human Rosources, said the state could lose as many as 10,000 jobs in the next 20 years and as many as 20,000 workers could need retraining.

The proposed department would include 1,421 employes -- all but 10 now working in various parts of state government on job programs.

The 10 new positions would cost the state an additional $304,000 a year, which would be paid out of new federal funds.

If the legislature approves the new department, Hughes' 14th cabinet secretary would be in place by next October.

At today's hearing on $169,000 earmarked for the department in the 1984 budget, Hughes aide Ben Bialek told subcommittee members that the governor considered other methods for implementing the new federal act. But, Bialek said, he decided that a full department with a cabinet-level secretary is necessary to "provide proper focus and equal status for employment and job-training issues."

Just as Bialek began his presentation, Del. Philip C. Jimeno (D-Anne Arundel) interrupted: "I'd like to ask when did all this [planning for the department] start?" Before Bialek could answer, Chairman Nancy K. Kopp (D-Montgomery) replied, "Just before the primary."

At the end of the hearing Kopp, who doubted whether a new department was a good idea, said she thought it would be carefully scrutinized by the legislature, possibly modified and then, most likely, passed.

"There'll be a lot of vocal objections but the governor wants it. Labor wants it. I'm not one lie down in front of a locomotive," said.