Virginia Democratic Senate candidate Richard J. Davis today ripped into his Republican opponent, U.S. Rep. Paul S. Trible, for a "lack of integrity" and "demeaning, divisive tactics" in connection with a controversial memorandum purportedly linking Davis to national labor political money.

Davis' unusually tough attack represented an escalation in a flap over the campaign memo, which has put Trible on the defensive since it was first disclosed in mid-August.

Trible campaign spokesman Neal Cotiaux later dismissed the Davis charges. "This whole matter is a non-issue," he said.

Authored by Trible campaign manager Judy Peachee, the Aug. 11 memo described a New York meeting at which Davis staffers previewed TV spots and then allegedly solicited "$3,000 each" from representatives of 75 labor unions. Peachee's account -- attributed to an unnamed "reliable source" -- said that Davis staffers asked that contributions be withheld until after a Sept. 30 federal reporting deadline.

After obtaining a copy of the memo, Davis staffers last month insisted that no such meeting had ever taken place and branded the document a "100 percent, total fabrication."

Today, Davis, who has been accused by Trible of ducking substantive issues in the campaign, stepped up the pressure. He charged that Trible's failure to repudiate the memo called his credibility into a question. "There seems to be a lack of integrity on some of the basic things," said Davis, at a State Capitol news conference.

"It would have been very easy for the candidate to say we made an error. . . But to have been unwilling to repudiate what was an obvious misrepresentation of fact, to me, attacks the integrity of the candidate and that attacks the integrity of the whole campaign."

The 61-year-old lieutenant governor, who has been endorsed by the Virginia AFL -- CIO, also charged that the memo was part of a "very studious effort to divide one group of Virginians from another (and) I reject that divisive action and demeaning tactics. . . They have tried to impose on me the tag of labor candidate with the idea that would make me unpopular as a Virginia candidate."

Trible spokesman Cotiaux today refused to respond to any questions about the memo, saying the congressman "has stated his position before and I'll not repeat it." Although Trible has refused to comment directly about the memo, Peachee initially defended the document in a Aug. 16 statement, stating that its "key elements" were correct.

In that statement, Peachee insisted there was a meeting of the AFL-CIO's Committee on Political Education (COPE), at which the Virginia campaign was discussed.

That statement -- the last detailed comment made by the Trible camp -- failed to make any mention of the other details in the initial memo, such as the presence of Davis staffers, the airing of television spots and the solicitation of funds.

"Congressman Trible is committed to an issue-oriented campaign," said Cotiaux . "We believe all Virginians want to choose the next U.S. senator on the basis of a thorough discussion of the issues and that is what he intends to do every day from now until the election."

Cotiaux referred, for example, to Trible's detailed speech in Charlottesville today defending the full Reagan administration tax cut enacted by Congress last year -- an issue on which the two candidates are at odds.

Davis, who was joined by Gov. Charles S. Robb and Attorney General Gerald L. Baliles, also used the occasion to unveil what he said would be the new theme of his campaign -- "Listening to Virginia."

"My opponent says I don't do enough talking," he said. "I think perhaps he does too much. It's more important to listen to Virginians than perhaps talk."