Virginia Democratic Gov. Charles S. Robb, in one of his strongest statements on civil rights, called tonight for a recommitment to the "aggressive enforcement" of the nation's antidiscrimination laws.

"There must be no doubt about which side the federal government takes in civil rights enforcement cases," Robb said in remarks prepared for a speech in Chicago tonight. Robb accused the Reagan administration, at best, of practicing "benign neglect" of social ills.

"Our nation will never achieve its full productive potential as long as discrimination denies some of our citizens opportunities to participate," Robb said in a tribute to Roland Burris. Burris, who is black, is treasurer of Illinois and a leading official of the Democratic National Committee.

Robb, the son-in-law of President Lyndon B. Johnson, said the country never achieved Johnson's "Great Society," and called for a "reawakening -- a new conciousness" for the Democratic Party to "remain true to the heart and soul of our party and meet the challenges the future has brought us."

Robb, who many politicians say is considering a role in national politics after his term as governor ends next January, warned that Democrats could not simply go back to establishing or supporting many government programs begun during Johnson's terms.

"We cannot meet this challenge by adhering rigidly to old approaches," said Robb, who suggested the party must become identified with strong economic growth as well as concern for minorities and low- and moderate-income Americans. Robb, whose administration has set new records in the hiring and appointment of blacks and women to public boards and commissions in Virginia, also warned against "the trap" of quotas that too often become "tools of those who discriminate."

Robb endorsed approaches to several issues Democrats see as keys to rebuilding the party, including civil rights enforcement, a fair and equitable assault on the nation's spiraling deficits and modified involvement of business in government to provide jobs.

The speech was sharply different in tone from Robb's address to the Democratic National Convention in San Francisco last summer. In that talk, Robb warned that the national party must be prepared to say "no" to special interests, even if it suffers short term losses of support.