Four national conservative groups yesterday endorsed Virginia Rep. Stan Parris' bid for the Republican nomination for governor, attacking his opponent, Wyatt B. Durrette, as lacking the credentials of a "true conservative candidate."

"Although Wyatt Durrette claims to be the true conservative candidate, the record proves that his allegiance to the conservative ideology is shaky at best," said Robert Heckman, chairman of the Fund for a Conservative Majority.

His comments were made in Arlington as officials of the fund, the Committee for the Survival of a Free Congress, and Citizens for Reagan made a swing through the state, urging conservatives to support Parris. The Christian Voice Moral Government Fund, a political action committee of evangelical Christians, also endorsed Parris but did not send a representative on the tour.

Many Virginia Republicans say that the candidate who is perceived as the most conservative is likely to win the party nomination at a convention May 31 in Norfolk.

The fund, a major conservative fund-raising group, also said it sent mailings this week to 26,000 Virginia conservatives and plans to spend $25,000 on the gubernatorial campaign, Heckman said. The other groups say they have no funds appropriated but plan to organize and mobilize supporters on behalf of the Northern Virginia congressman.

Earlier this week, Durrette, a Richmond lawyer, received the endorsement of the Young Americans for Freedom and the American Citizens for Political Action, according to spokesman Don Harrison. He said neither group pledged any funds.

Although Durrette and Parris were considered moderates by many when they represented Fairfax County in the Virginia General Assembly, both have heavily courted conservative groups in recent years.

The conservative endorsements come shortly before 15 major mass meetings Tuesday, when 700 to 800 delegate votes will be at stake. At least 1,996 votes are needed to win the nomination.

Both sides predict Durrette, the party's acknowledged front-runner, will do well Tuesday, particularly in the Richmond mass meetings. But the Parris campaign says it will win many of the major meetings after Tuesday, including those in Northern Virginia in April and May.

Durrette claims to have 137 of 171 votes decided at nine February meetings, a figure disputed by the Parris camp. Durrette has raised $474,000 and has $110,000 in the bank, said Harrison. As of Jan. 15, Parris had raised $522,000 and had $381,700 cash. A Parris official declined to give more recent figures.

The conservative groups criticized Parris' endorsement of the Equal Rights Amendment but said that was the only issue on which they disagreed with him.