Virginia Gov. Robert F. McDonnell is encountering legal obstacles in his effort to expand his influence on the board overseeing construction of the multibillion-dollar Silver Line rail project.

In the past two months, McDonnell (R) has made three appointments to the board of the Metropolitan Washington Airports Authority, but none of his selections have been seated.

One appointment is tied up in a dispute over whether McDonnell acted properly when he removed board member Dennis Martire and replaced him.

Martire, the only board member with formal ties to organized labor, sued in federal court in the District to block his removal from the board, arguing that the governor’s action was politically motivated. McDonnell denied that Martire’s removal was politically motivated. Martire is vice president and Mid-Atlantic regional manager of the Laborers’ International Union of North America.

Martire had recently come under fire for travel expenses after a federal audit found that in addition to other expenses, Martire had spent more than $9,000 on a plane ticket to a transportation conference in Prague. But he and McDonnell also had clashed over the inclusion of a union-friendly provision as part the construction deal for the second phase of the Silver Line.The provision was later dropped.

Meanwhile, officials from the authority have petitioned a judge in Fairfax County to tell them which appointee should be seated — Martire or McDonnell’s appointee, McLean businesswoman Caren Merrick.

Martire and Merrick have been sidelined while officials seek clarification.

The gap has left some officials worried that Virginia’s interests are not being represented on the board. On Wednesday, during the authority’s monthly board meeting, Vice Chairman Tom Davis raised the issue and attempted to remedy the situation by asking board members to allow Merrick to be seated until the matter could be settled by the court. But Davis, a former congressman from Virginia, was unable to secure the support to move the issue to a vote. The question of who — if anyone — should take the seat in the interim will be taken up at the board’s next meeting.

McDonnell’s two other appointees, Lynn Chapman of Ashburn and Elaine McConnell of Springfield, also are waiting to begin their terms.

The authority’s board is made up of members from the District, Maryland, Virginia and the federal government, and legislation passed by Congress and by the Virginia General Assembly expanded the board’s membership from 13 to 17.

But before the expansion can take effect, the District must approve the amendment to the law governing the authority.

“We are waiting for the District of Columbia to approve the amendment,” said Philip Sunderland, the authority’s vice president and general counsel. “We believe that we are unable to seat the new appointees until the District takes action and the compact is properly amended.”

Four of Virginia’s five seats are filled, and under the expansion, the commonwealth will add two members, Chapman and McConnell. Maryland has two representatives and will gain one. The District has three and will add one. And the federal government holds three seats, with one of them vacant since the death of Charles Snelling this year.

The earliest the D.C. Council could take up the matter is September when members return from their summer recess. And even if the council passes the pertinent legislation, it’s not clear whether McDonnell’s appointees can be seated. The bill pending before the council includes a provision that would prohibit new board members from being seated until all board appointments are completed. That language was not included in the bill approved by Congress and by the Virginia legislature.

Jeff Caldwell, a spokesman for McDonnell, said that D.C. officials are not permitted to add conditions or requirements beyond what was in the legislation passed by Congress. Doing so, Caldwell said, is “unconstitutional.”