Gov. Charles S. Robb asked the legislature today to overturn a controversial new criminal libel measure that would impose jail terms on persons who distribute "materially false" information about political candidates.

After the law was passed by the General Assembly last month, it provoked outcries from civil liberties groups and newspaper publishers who view it as a dangerous assault on First Amendment guarantees of free speech.

Robb said today in a brief statement that he apppreciates the frustration over campaign falsehoods that led to the law's passage but added that the problem is "best left to the electorate or the safeguards provided by the civil law of libel and slander."

Robb's announcement infuriated the law's chief sponsor, Del. Floyd Bagley (D-Prince William), who complained that the governor had not bothered to consult with him before formally requesting that his bill be killed.

"Anything I might say would not be printable," said Bagley, who is running for the U.S. Senate, when asked about the governor's request. "It's highly irregular for the governor to veto a bill without even talking to its patron. I'm shocked."

Actually, Robb's action was not a veto. Bagley had added his bill as an amendment to a much broader omnibus elections act, the rest of which the governor stands ready to sign into law. Instead of vetoing the whole elections bill, Robb simply asked the legislature to pass a new amendment deleting the campaign libel provision when it reconvenes for a special veto-override session next Wednesday.

If the legislature refuses to pass the proposed amendment by a majority vote of both houses, Robb then would have the option of either vetoing the entire elections bill or signing it with the unwanted Bagley language. A spokesman declined to say which option the governor would choose.

The request to delete Bagley's bill was one of two major amendments the governor proposed early this morning, shortly after the midnight deadline for gubernatorial action on the 706 bills passed by the General Assembly during its two-month session that ended March 13. Robb also asked the legislature to appropriate $61.1 million for a 4 percent across-the-board pay raise for the state's 73,000 employes, to take effect July 1. The funds would be shifted from other areas, including a special "economic contingency" fund that generally is used for emergencies.

Pressure for a pay raise began building last week after it was disclosed that, in passing the budget, Robb and the legislature had relied upon a outside consultant's report that contained over $39 million in arithmetical errors. The report by the prominent international consulting firm of Hay Associates had erroneously concluded that state salaries were already competitive with pay scales in the private sector.

Robb also proposed amendments to 37 other bills, including a hotly contested gasoline tax measure, but they were all described as technical in nature. Among the 645 bills that Robb signed into law were two measures that would provide Medicaid funding for abortions in cases of rape and incest and when there is a "gross fetal deformity." Both were vetoed last year by former Republican Gov. John Dalton.

Of all the bills on Robb's desk, however, the most controversy had been generated by the Bagley bill on criminal libel, provoking a constitutional debate over free speech and the First Amendment. Bagley originally had decided to introduce the measure after his Republican opponent in the last election circulated a "green sheet" to voters that, he said, contained a "pack of lies" about his record in the legislature.

"I can't believe the governor believes it is in the public interest to have the right to lie in a political campaign," Bagley said. "How are you ever going to get anybody into politics if any Joe can go out there and tell lies about you?"

Groups ranging from the American Civil Liberties Union to the Libertarian Party had lodged protests, contending that the law would have a dangerously chilling effect on campaign speech. In part, they argued, this is because of the impossibility of sifting out falsehood from truth in the highly charged atmosphere of political campaigns. One ACLU lobbyist said that, if strictly interpreted, the law could open up scores of state legislators to criminal prosecution for distributing their own campaign brochures.