Hordes of ambassadors, congressmen, senators and Carter administrators streamed into international lawyer Sylvan Marshall's house Saturday night for a party honoring Clement Zablocki, chairman of the House Committee on International Relations. So many, in fact, that one of the Marshalls' neighbors called the police when he thought former Sen. Hugh Scott's car was blocking his driveway.

"Lousy SOB," said the irate Scott about the neighbor. "It was a Volkswagen that was blocking the driveway, not my car."

Scott's feathers were soon unruffled, however, by the Marshall's spacious house and a buffet that featured omelettes-on-request and beef fondue.

The food didn't seduce National Security Adviser Zbigniew Brezezinski, at least not at first. For almost half an hour, Brezezinski stood deep in conversation near the Marshalls' doorway with Russian Ambassador Anatoly Dobrynin. When asked what they talked about, Brzezinski waved away the question with the announcement that he was on his way to the buffet table.

House minority Leader John J. Rhodes was unimpressed with the intimacy between Brezezinski and Dobrynin. I've got Dobrynin's private number. I don't have Jimmy Carter's though," he confided as he and his wife entered the crush of people.

There was a heavy mix of international, governmental and congressional among the nearly 250 guests, who included Danish Ambassador Otto Rose Borch; Iranian Ambassador Ardeshir Zahedi; British Ambassaddor Sir Peter Ramsbotham; House Banking, Currency and Housing Chairman Henry Reuss, and former U.S. Chief of Protocol SHirley Temple Black.

Though there was enough clout gathered to have held a good-size foreign affairs conference, one diminutive, elderly woman with a black net shawl around her shoulders complained that she didn't know a single person. "Everything I have on is antique. I'm an antique too, perhaps that's why I don't know anyone here."

It was a massive group for a purely social occasion, but that is what it was, maintained host Marshall, a partner in the law firm of Marshall, Leon, Weill and Mahony.

"I don't lobby on Capital Hill," Marshall said. "This is purely a social gesture. Zablocki and I are very old friends of many years standing."

"We're just old friends," Mara Marshall emphasized. "We were in Mexico together when Kissinger went there."

Trips to foreign countries weren't on former Protocol Chief Shirley Temple Black's mind, though. "I'm only in Washington for five or six days." she said, adding that her husband would be in the city frequently working on a project for the National Science Foundation. But she won't miss Washington. "I enjoy being a housewife, something I've done now for the past 20 years. I'll come to the city from time to time with my husband, though."

Syrian Ambassador Sabah Kabbani felt there was no better place to live than Washington, but was more interested in discussing the reported CIA links with Jordan's King Hussein.

"I think there is something suspicious about the timing of the whol thing," he said. "If this has been going on for so long, why was it suddenly revealed just when (Secretary of State Cyrus) Vance was going to the Middle East?No, I don't believe the charges. And especially because they came out now."

The guest of honor's daughter, Jane Zablocki, was overwhelmed by the whole party. Standing in a corner away from the crowd, eating an omelette, she said," I don't really like these things. I just want to take my shoes off."