D.C. Council Chairman Kwame Brown, center, talks to Jim Dyke Jr., left, and council member, Tommy Wells following the council's opening session of 2011. Dyke recently was appointed to the Metro board by Va. Gov. McDonnell. (MATT MCCLAIN/THE WASHINGTON POST)

Fairfax County will lose a seat on Metro’s board of directors, and Arlington County’s representative will lose voting power to make way for an appointee by Virginia Gov. Robert F. McDonnell.

The changes follow a push by McDonnell for the state to have more representation on the board.

Last fall, McDonnell appointed Jim Dyke, a Northern Virginia lawyer and business leader, to the Northern Virginia Transportation Commission (NVTC) , which appoints four representatives to the 16-member Metro board.

Dyke is expected to join the Metro board Thursday, just as it begins discussing next year’s budget. He will become a principal, voting member of the board, taking the seat of Mary Hynes, chair of the Arlington County Board.

Hynes, who has been on the Metro board since January 2011, will assume one of the board’s eight non-voting alternate seats, which is currently held by Jeff McKay, a member of the Fairfax County Board of Supervisors.

McKay, who has served on the Metro board since January 2008, will step down. Cathy Hudgins, the chairman of the Metro board who is a supervisor in Fairfax County, will remain on the Metro board.

Hynes on Friday said the change will be a difficult one. The concern, she said, is that Dyke represents Virginia and that the state “has a different priority on funding transit than we do in Arlington. . . . Transit is crucial for us. If it doesn’t work, our community shuts down.”

McKay said his stepping down is a disservice to riders. “It is clearly a political power play by the governor,” he said. “It is a big mistake for the transit agency because this has to do with who can run a transit agency better: local government or the state? It is clearly local government.”

Sean Connaughton, Virginia’s secretary of transportation, encouraged McKay to remain involved. He said McDonnell plans to meet with D.C. Mayor Vincent Gray and Maryland Gov. Martin O’Malley next week to discuss Metro governance and safety.

“The commonwealth is committed to working with the localities and all the stakeholders to address the current challenges facing Metro,” he said.

Metro’s board and its organizational structure underwent harsh criticism after the 2009 Red Line crash that killed nine people and injured dozens. The 16-member board has tried to revamp how it governs while also dealing with turnover. Dyke will be the tenth new member to join the board since last January.

Local transportation groups along with officials from the counties, the District, Virginia and Maryland select 12 board members. The General Services Administration selects four members.