A move by Congress may allow members of the board that oversees Reagan National and Dulles International airports to be removed by their appointing bodies and increase the size of the panel, which is supervising the construction of the Metrorail extension to Loudoun County.

Rep. Frank R. Wolf (R-Va.) has pushed for legislation that would expand the board of the Metropolitan Washington Airports Authority from 13 to 17. Under his plan, Virginia would get two new appointments and Maryland and the District would each get one additional member.

Wolf’s legislation would also prohibit members from serving past the end of their terms. Members could also be “removed for cause.” The governors of Maryland and Virginia and the mayor of the District could remove their respective members. The executive branch of the federal government already has that authority.

The changes are part of the appropriations bill for the U.S. Transportation Department that is being considered by Congress. The House is expected to vote on the bill Thursday and the Senate on Friday.

The airports authority board voted in September to authorize Chairman Charles Snelling to publicly oppose Wolf’s efforts.

Snelling declined Tuesday to comment on the legislation.

“I do not think that it would be appropriate for me to comment while this matter is being considered by the Congress,” he wrote in an e-mail.

A monthly meeting of the board is scheduled for Wednesday.

The authority manages Dulles and Reagan airports, plus the construction of the $6 billion Dulles rail project that will eventually run from Tysons Corner to Loudoun. The first part of the rail project is under construction but may be as much as $150 million over budget.

Watchdogs have expressed concern about the airports authority’s operations and the board’s oversight. Wolf and other lawmakers had requested that the Transportation Department’s inspector general audit the authority’s operations. That review is expected to be completed this spring.

“These airports are the economic engine for the region, and with MWAA responsible for the Dulles rail project, ensuring that Virginia has more say and that board members are current and more accountable is more important than ever,” Wolf said in a press release.

Members of the authority’s board are appointed as representatives of Maryland, Virginia, the District and the U.S. president for six-year terms.

The three board members appointed by the president are required to live outside the Washington region. Board members for the authority have typically served until a replacement is in place.

Wolf cited an incident this year in which a board member, whose term expired in January 2009 but who had not been replaced, was voting by proxy from Africa. The board member was replaced in April.

Wolf also said a replacement had yet to be named for William Cobey, a board member whose term expired in May 2010 and who is still serving. The term of Robert Brown — the chairman of the board’s finance committee — expires this month. Wolf said it is “unclear if the replacement process has begun.”

“Board members need to be replaced when their terms end,” Wolf said in the release. “It’s not their fault that they aren’t being replaced, but if the officials making the appointments know that the seat is going to be vacant, maybe there will be more of an incentive to make appointments in a more timely fashion.”