The National Park Service effectively encouraged construction of a Mormon chruch along the George Washington Memorial Parkway near Mount Vernon after the service's congressional liaison officer, who is Mormon, met privately with park officials.

Until then strong neighborhood opposition to the proposed church and the traffic it would bring appeared to have doomed its chances for approval from Fairfax County officials.

But when a hand-carried letter from the park service's regional director arrived at the county offices the day of a crucial board decision, the county's opposition to the church abruptly ended. The park service letter implied that it would grant the church a rare parkway access permit and allow the church to use of a narrow dead-end lane off the highway as the sole entrance to the church.

The Fairfax Board of Zoning Appeals, no longer faced with putting church traffic onto a residential street, approved the church's construction at a meeting last spring.

Park service congressional liaison Ira Whitlock, who said in a recent interview he had been asked by church elders to intervene in the case, defended his actions as proper. Whitlock also said that a congressman "concerned about discrimination against the church" had asked him to look into it. He declined to identify the congressman.

Whitlock acknowledged that he visited the church site with Manus J. Fish, the regional park official who wrote to Fairfax officials, before the zoning board decision. "I met Fish as a private citizen. I have the same right to discuss this with him as any private citizen."

In addition, Whitlock alleged that his boss, Secretary of Interior Cecil D. Andrus, was exerting pressure on behalf of the citizens opposed to the church and had made calls on the issue. Whitlock said he was attempting to counteract pressure from his boss to ensure that equal pressure was brought on both sides and a fair decision was made.

"But there's much more pressure . . . brought by calls from a secretary than from a staff person like me," Whitlock said.

A spokesman for Andrus, who lives in McLean, denied yesterday that the secretary had any interest in the Mormon church proposal and called Whitlock's charges "totally false. . . . The secretary had no knowledge that a church was even being built in that area."

Fish, the regional park director, said he met privately with Whitlock on the issue but said the meeting did not affect his actions.

While Fish's letter to county zoning officials appears to promise support for the church project -- at least no park service objections to it -- the letter fails to mention that the park service cannot approve a permit for widening of the narrow lane onto the parkway without first conducting an environmental review, possibly with public hearings.

Whitlock is a member of the Alexandria ward or parish of the Church of Jesus Christ of Latter-day Saints, where members of the proposed Mount Vernon Mormon church now worship.

Members of the Stratford-on-the-Potomac Citizens Association have challenged the county's approval of the church in Fairfax County Circuit Court but their lawsuit is not expected to be decided until early next year.

It alleges that the Mormon application -- for a special use permit to build a church in a residential zone -- failed to contain any estimates of the traffic impact the church would have on the parkway or nearby streets. It also contends that the church would be the first institution ever permitted to front on the 49-year-old parkway and that the church would violate a longstanding Fairfax policy of prohibiting other than low, residential housing near scenic parkways.

Despite the letter to Fairfax officials, the park service has yet to grant the permit allowing the church to have an entrance on the parkway.