A House subcommittee voted yesterday to beef up the Office of Civil Rights in the proposed Department of Education, but the proposal remained under attack from black and labor spokesmen fearing loss of political clout if a new department is created.

Rep. Shirley Chisholm (D-N.Y.), a black, bluntly told the subcommittee earlier this week that effective coalitions of labor unions, black groups and spokesmen for the poor had been put together over the years to support education programs under the jurisdiction of the House Education and Labor Committee and administered by the Department of Health, Education and Welfare.

"Now, to thoughtlessly destroy these coalitions . . . in order to achieve the dubious goal of formation of a separate department appears foolhardy," she said.

Moreover, she said, if education is divided from HEW, there may be a move to "split the House Education and Labor Commitee and, in this way, divide the power of labor and its allies.

Andrew J. Biemiller of the AFL-CIO made the same arguement on Monday: "Rather than encouraging the traditional go-it-alone tendencies of many educators to want to set education off by itself, we should launch a coordinated approach to the major problems our nation faces - poverty, equal educational opportunity, welfare and health security. Labor has been instrumental in building coalitions around these issues. A fragmentation of health, education and welfare adminstration will only encourage narrow thinking and a fragmentation of the political voice that now speaks for all of them."

The testimony of Chisholm and Biemiller reflects fears that the new department will be run by educational professionals who have little desire to press civil rights in education and little interest in coordinating government welfare, health and poverty programs with eduction in a comprehensive approach to aid to poor and minority children. They believe such an approach can be better achieved by leaving education in HEW.

These fears have created a tug-of-war over the bill between welfare oriented groups represented by labor and black orgaiization, and professional organizations like the National Education Association, although there is much overlapping. Many educators believe a separate department will mean a louder voice and more money for education.

The bill, which would create a new department with about 18,000 employes and a $4-billion annual budget, has already been approved by the Senate Governmental Affairs Committee.

Yesterday, the House Government Operations Legislation subcommittee adopted the provision to beef up the civils rights office to mollify some black groups.

Sponsored by Rep. Benjamin Rosenthal (D-N.Y.), who would like to postpone the whole bill until next year, the provision would ensure that the 1,200-person Office of Civil Rights in the new department could have power to make the direct reports to Congress. The office also would be able to complain to Congress when its budget is cut, to collect whatever information is needed to enforce civil rights and equal opportunityin education, and to hire qualified personnel to enforce the laws.