The Justice Department filed suit against convicted former House member Joshua Eilberg yesterday, claiming that he owes nearly $150,000 to the government.

The Pennsylvania Democrat pleaded guilty earlier this year to a federal conflict of interest charge in connection with money he received from his law firm after the firm helped a Philadelphia hospital get a $14.5 million federal grant.

Under a plea-bargaining agreement, Eilberg was fined $10,000 but received no jail sentence. He was defeated in his bid for reelection shortly after being indicted last fall, and in March he was suspended from practicing law in Pennsylvania by the state Supreme Court.

Yesterday's suit was not surprising, because the plea-bargaining arrangement left open the possibility that the government might seek civil recovery. Eilberg's attorney, John Rogers Carroll of Philadelphia, could not be reached for comment yesterday.

The complaint, signed by Peter Vaira, the U.S. attorney in Philadelphia, asks that Eilberg pay the government $35,172 he allegedly received illegally from his law firm for the hospital grant.

It also asks that Eilberg pay more than $114,000 in penalties for alleged misuse of his congressional telephone credit card between 1973 and 1978. The alleged misuse was apparently unrelated to the hospital grant.

United Press International in Philadelphia reported that Vaira plans to subpoena Eilberg's congressional phone records from the House. So far, Congress has balked at turning over the records on grounds that they are protected by the Constitution's "speech and debate" clause.

Eilberg got national attention early in 1978 when David Marston, then the Republican U.S. attorney in Philadelphia, complained that the congressman had called President Carter trying to get him removed.

Attorney General Griffin B. Bell later fired Marston, touching off a wave of bad publicity about the administration's promise of selecting prosecutors on merit alone.