Mayor Marion Barry has asked the federal government for a $20 million grant to help restore the historic Willard Hotel downtown because the private developer in charger of the project, who once scoffed at public assistance, has been unable to secure adequate private financing.

A representative of developer Stuart S. Golding said yesterday that "a lot of cuts" may have to be made in the restoration plans if the federal funds are not approved. There was no immediate indication yesterday of the likelihood of such approval.

Golding, chosen as developer for the project in 1978, has repeatedly sought to delay the project, citing soaring interest rates and construction costs. He faces an April 1 deadline for beginning construction, and has been unsuccessful in his attempts to have the deadline delayed.

Golding's son Ken, who handles the Florida developer's affairs in the District, said yesterday that he and his father are "confident" of being able to obtain $70 million in private financing, which would complete the estimated $90 million cost of the restoration.

"It's tough to get a $90 million mortgage these days, it really is," Ken Golding said. "Financing was not as difficult to come by a year ago. The market was not as bad."

Ken Golding blamed his problems is obtaining full private financing on interest rates, which have skyrocketed in the last year, and on inflation, which has driven up costs.

When restored, the hotel, located at 14th Street and Pennsylvania Avenue, will anchor a vital corner in the overall refurbishing of the avenue being coordinated by the Pennsylvania Avenue Development Corporation (PADC).

The Willard falls under jurisdiction of the PADC, which was established in 1972. Thus, the request for federal assistance to bail out the project effectively amounts to one arm of the federal government seeking salvation from another -- meaning that the city and the developer are seeking, in effect, a federal bail-out of a project already under control of a separate federal entity.

"He [Golding] didn't go through us on this," said lawyer Max N. Berry, head of the PADC. "Whether he needs the grant is really his business. We certainly applaud any progress on the Willard."