The Club for Growth on Wednesday endorsed former state Rep. Kevin Calvey (R) in the race to succeed Rep. Mary Fallin (R).

Calvey received the first candidate endorsement of the 2010 cycle from the conservative anti-tax group.

Fallin made her gubernatorial bid official over the weekend, and Calvey is one of several Republicans expected to seek her 5th district seat.

Urologist Johnny Roy, an Iraqi immigrant, is also running, and state Rep. Mike Thompson is looking at the race. Calvey and Roy both ran in the GOP primary in 2006, the last time the seat was open.

Corporation Commissioner Jeff Cloud and Oklahoma City Mayor Mick Cornett, who lost to Fallin in the GOP runoff in 2006, are also mentioned as possible Republican contenders.

Calvey served in the Oklahoma state House from 1998 to 2006. The club’s political action committee endorsed Calvey in the 2006 race, where he finished fourth with 10 percent of the vote.

“Given Kevin Calvey’s record in the Oklahoma House of Representatives, we have every reason to believe he will be a strong fiscal conservative in Congress,— Club for Growth President Pat Toomey said in a statement. “As Congress seems more and more determined to spend the country into oblivion, Washington could use a fighter like Kevin Calvey to stand up for taxpayer’s hard-earned money.—

The 5th district is strongly Republican, and Democrats are not expected to contest the open-seat race in 2010.