Health and Human Services Secretary Margaret M. Heckler said yesterday that the administration is at work on a plan to maintain health care for the unemployed and that she hopes one can be passed by Congress "before the end of the summer."

Heckler, testifying before a Senate Appropriations subcommittee on her department's proposed $288.8 billion budget for fiscal 1984, told Chairman Lowell P. Weicker Jr. (R-Conn.) that HHS is working on the matter with Sen. David F. Durenberger (R-Minn.), Finance Committee Chairman Robert J. Dole (R-Kan.), the Office of Management and Budget and the Labor and Treasury departments.

She gave no details except to say that the administration wants to avoid creating a new entitlement program.

Other sources said the administration has no specific plan in mind yet.

The Congressional Budget Office has estimated that nearly 11 million people have lost employer-provided health insurance because of unemployment.

As a remedy, Dole initially wanted to add health care for such people onto last month's Social Security bill, but decided not to do so because the administration was unhappy with his proposal.

It then was introduced as a separate bill by Dole, Durenberger, John Heinz (R-Pa.) and other senators.

It would provide $1.8 billion in grants to the states over the next two years for medical services to the families of those receiving unemployment insurance who previously were covered by group health plans at work.

One source said some administration figures believe the Dole bill is too complicated, could easily be converted by Congress into some sort of permanent entitlement and may focus aid on the least needy of the unemployed.

In other business, Weicker lashed out yesterday at administration proposals to cut about $1.6 billion from about $70 billion in HHS programs under the control of his subcommittee.

Weicker predicted that "a good portion" of the $1.6 billion will be restored.

Although Weicker said he was pleased when Heckler announced that the administration wants to fund 5,000 new research grants in the National Institutes of Health next fiscal year, instead of cutting them by one-third as it initially proposed, he called it "sleight of hand" when Heckler said $140 million for the extra grants would have to be found by cutting back other NIH funding.

Weicker also called proposed cuts in the developmental disabilities program, various health programs and block grants for social services and low-income energy assistance "balancing the federal budget on the backs of the weakest elements of our society."

Saying that the administration budget "shows something less than the requisite level of compassion" for the poor, ill and disabled, Weicker demanded that the administration "put its money priorities on the side of life . . . take care of flesh and blood."