Democrat Michael Dukakis, trying to regain momentum for his presidential campaign, said Friday he was rehiring former campaign aide John Sasso because "I want the strongest team I possibly can" for the battle against Republican nominee George Bush.

Bush meanwhile appeared before vacationers on the sands of Belmar Beach, N.J., to press his attack on Dukakis' environmental record as Massachusetts governor.Dukakis, he said, "fought to allow Boston sludge to be dumped off New Jersey's shore - the very shore on which he had the nerve to stand and promise clean water." Bush added sarcastically: "Nice guy."

Dukakis, winding up a campaign swing through the West Coast, announced in San Jose, Calif., that he was bringing back the former campaign manager who had resigned last Sept. 30 after Sasso admitted helping torpedo the campaign of party rival Joseph Biden of Delaware.

Dukakis said Sasso, who will be vice chairman of his campaign, is "a uniquely talented individual who can provide real strength."

The governor denied that Sasso's return was linked to Dukakis' recent decline in public opinion polls in his race against Bush.

Sasso had previously engineered Dukakis's successful campaign to recapture the Massachusetts governorship after a term out of office, and directed Dukakis's presidential campaign until he resigned in September 1987.

Sasso left after admitting that he circulated a videotape demonstrating Biden had borrowed without attribution some deeply personal remarks by British politician Neil Kinnock. Only two days earlier, Dukakis said he had been assured no one on his campaign staff was the source of the videotape.

Dukakis and Bush took advantage of the timely concerns - the opening of school and a summer haunted by the specter of waste-strewn shorelines - to go after voters before the official Labor Day opening of the campaign season.

"While they've invested billions in Star Wars, we've developed a regional network of star schools," Dukakis said Thursday in California while contrasting his achievements as Massachusetts governor with the inaction of the Reagan administration.

"Where was the man who now says he wants to be the `education president'?" Dukakis said in Oakland. "He was playing hooky. He was nowhere to be found."

He charged the Reagan administration has eliminated remedial math and reading programs for 500,000 poor children, cut teacher retraining, and "led an assault on college loans and grants."

He said that in Massachusetts he had quadrupled scholarship assistance to low- and middle-income students and invested in Professional Development Centers to help teachers update their skills.

The Reagan administration sought cuts in the remedial programs in 1981 but was unsuccessful. In an April 1988 report, the Education Department said the number of children in remedial programs had dropped from 5 million in 1979-80 to 4.5 million in the 1985-86 school year.

Bush, after a rally Thursday into Dukakis' back yard, where he charged the governor failed to act swiftly against pollution in Boston Harbor, continued his campaign as a "lifelong environmentalist" on the Delaware and New Jersey shores. Dukakis called Bush's newfound commitment an "election-year conversion."

Bush also criticized Dukakis for promising to end the dumping that has left medical waste cluttering New Jersey beaches, when Dukakis himself as governor asked for federal permission to dump waste off New Jersey.