Virginia Republican gubernatorial candidate J. Marshall Coleman rejected suggestions his campaign is floundering yesterday and called for "a mutual cease-fire" in the negative media war he has been waging with Charles S. Robb, his Democratic opponent.

Coleman's call for a campaign based on specific issues and one "worthy of Virginia's standards of civility and grace" came on the eve of a massive GOP television campaign. The ads are part of an effort by the Republican National Committee, whose officals are troubled by Coleman's showing in the polls and are fearful that a GOP defeat in Virginia would embarrass the Reagan administration.

Flanked by Gov. John N. Dalton, former governor Linwood Holton, Sen. John Warner and members of Virginia's Republican congressional delegation, Coleman came to Washington yesterday to denounce what he termed Robb's "misleading advertising and . . . innuendoes" that have required "strong treatment in response."

Coleman, the state's attorney general, rejected suggestions that his campaign -- trailing by as much as 11 points in recent polls -- is in trouble. "We are just disappointed that this campaign can't be conducted on the basis of issues."

He stopped short of acknowledging that his own advertising, which has caused a furor and anger among some of his own backers, was too negative. "I acknowledge one thing," he said in a news conference at the Hyatt Regency. "That I responded every time a distortion developed to set the record straight. But I will be delighted to see that cease because it has been activated by the other side completely."

Robb spokesman George Stoddart charged yesterday that the Republican candidate was "very obviously worried about his stance in the polls and is very desperately trying to find an issue to talk about.

"I think Marshall is uncomfortable with discussions of his record . . . ," Stoddard said. "We call on him to stop his personal attacks and get back to the record."

Despite his suggestion of a hiatus in the media crossfire, Coleman is continuing to run television and radio commercials featuring Dalton chiding Robb for making "absolutely false" charges against his protege. Coleman campaign manager Anson Franklin says the ads, which began airing a week after Robb and Coleman had clashed over Coleman's drug enforcement record, were released in an effort to counter impressions that Coleman was "soft on drug crimes."

The negative ads began last month with a Robb radio commercial quoting Coleman saying that "marijuana is no longer a serious criminal problem." Coleman responded with an ad suggesting that the Democrat's charges "are enough to make you wonder what Robb's been smoking."

"If the other side resorts to innuendoes again we shall again be prepared to react as necessary," said Coleman yesterday. "But surely they must by now know that Virginia does not respond well to personal attacks."

Tomorrow, the Republican National Committee, which this week dispatched a top adviser to Richmond, will begin a $200,000 statewide television blitz suggesting that Coleman's election is necessary to the success of the Reagan presidency. The Robb campaign, by comparison, expects no similiar support from its national party headquarters.

The GOP ads will are calculated to enhance Coleman's image as a specific on the issues and brand him as a traditional Republican who keeps his promises. RNC strategists said their efforts are independent of the Coleman campaign and that any similarity in messages from the two organizations is "coincidence."

"I would assume," said Franklin, "that the people at the committee have seen our literature and know the tack we're taking and are tailoring their media to what we're doing."

The RNC ads, said one Republican media specialist, are among the first statewide efforts modeled on the advertising the party used in the Reagan victory last year. "One of the basic points is . . . that people seem to think that Republicans are more precise in talking about issues and that because of what Reagan has done, they keep their promises."

While RNC researchers did not work with the Coleman campaign in developing the advertisments, he said, "We read the papers and we have materials put out by both campaigns." The ads, the GOP strategist said, take as their starting point perceptions that Robb, by comparison, is "fuzzy on the issues."

Last year the RNC spent more than $4 million showing ads depicting Democratic leader Thomas P. (Tip) O'Neill running out of gas and an unemployed factory worker walking through an empty plant. Polling, RNC officials said, showed that voter opinion shifted against Democrats and toward Republicans by from 5 to 20 percent is areas where the commercials were shown.

The RNC television spots for the Virginia ticket, which will air as many as 78 times on a single station between now and Nov. 3, should give Coleman a nearly two-to-one edge in television exposure. A GOP film crew recorded people on the streets of Richmond last week. Clips of those who gave favorable responses by praising Republicans for their forthrightness and adherance to campaign pledges are featured in the commercials.

The commercials end with an announcer saying: "Republicans: They tell you exactly where they stand and they keep their promises."