A federal judge in Chicago has ordered the Department of Housingand Urban Development not to implement regulations for its Temporary Mortgage Assistance Payments program on the grounds that they violate the intent of Congress and an earlier court order.

In issuing the injunction, U.S. District Judge Hubert L. Will expressed a "continuing frustration" in his efforts "to secure reasonable implementation" of an earlier HUD mortgage assistance plan, known as the assignment program. He cited what he called HUD's "long, disgraceful history of footdragging" on assignments, and said it gave him no assurance that the department would do any better with TMAP.

The injunction is a severe blow to the TMAP program, which HUD had billed as a cheaper way of providing the same kind of help as the assignment plan. The department now either must appeal or rewrite its regulations. A HUD spokesman said no decision has been made, but either way means a long delay.

The judge's order is the latest episode in a legal battle that began in 1973 when a group of homeowners filed a class action claiming that HUD was doing little to help people facing foreclosure on their FHA or other HUD-guaranteed mortgages.

In 1976, a settlement was reached under which HUD agreed to revise its policy for accepting "assignment" of such mortgages. Under the assignment program, HUD pays off the lender, takes over the loan itself and receives payments from the homeowner. However, it will accept such an assignment only if the homeowner's difficulties arose through no fault of his own and if there is a reasonable prospect that he will be able to get back on his feet within three years.

But the settlement proved anything but final, and HUD and the plaintiffs have been in court off and on ever since, fighting over whether the department was living up to its obligations.

In 1980 Congress passed the TMAP program, under which lenders would keep the mortgages and receive payments directly from HUD. The department completed its rule-making process last fall and asked the court for permission to implement the new regulations.

Will ruled that the new rules would not live up to the requirements of the earlier settlements. And he was plainly exasperated, wondering at times in his April 7 opinion about HUD's good faith.

"It is clear to us that what HUD sought when it went to Congress and what it seeks now . . . is to scuttle the agreement with the plaintiffs and the commitment embodied in the agreement and to restrict even further the mortgage foreclosure assistance which it has so niggardly provided thereunder," he wrote.

The judge noted that he was not opposed to TMAP in principle. "The TMAP concept is one with considerable merit . . . so long as its implementation does not derogate the intent of Congress and the rights of mortgagors under the amended stipulation," he said. "Unfortunately, the proposed regulations do both."