SAN ANTONIO (Reuters) - The approval of a specialty Texas vehicle license plate which says "One State Under God" and shows three crosses has again put Texas Governor Rick Perry on the spot in the Republican presidential race.

The Texas Department of Motor Vehicles board, all of whom were appointed by Perry, voted 4-3 Thursday to approve the controversial plate, dubbed "Calvary Hill."

The approval came in the same week that Perry unveiled a television ad in Iowa targeted at evangelical Christians in which he criticized gays in the military and vowed to end what he called President Barack Obama's "attacks on religion."

So far, Perry has avoided commenting directly on the religious license plate decision. After the vote, Perry's office released a statement saying: "This was a decision for the DMV board and Gov. Perry was not involved."

But critics said the decision smacks of religious discrimination.

"It has become pretty clear that our governor is dismissive of religious beliefs other than his own, and now his governmental appointees have voted to send a message that Texas is unwelcoming to the religious faiths of some of its citizens," Kathy Miller, President of the Texas Freedom Network, an activist group opposed to the Calvary Hill license plate.

The issue has highlighted a danger for Perry, who is the only current state governor running for the Republican nomination, and he is vulnerable to criticisms of whatever happens in his state under his watch. Mitt Romney is a former Massachusetts governor and New Gingrich a former speaker of the U.S. House of Representatives. But neither holds office now.

The plate is the latest of some 130 special interest license plates approved in Texas over the past few years which promote everything from bicycling to various colleges and universities. Motorists who choose to buy the plate pay a surcharge, which is divided, with the state getting half, and designated private organizations the other half. In the case of Calvary Hill, a Christian-based youth anti-gang ministry in the east Texas city of Nacogdoches will get some of the money.

The Texas license plate flap is the second to receive national attention since Perry launched a bid for president during the summer.

The motor vehicle board in November rejected a plate showing the Confederate battle flag to commemorate the 150th anniversary of the start of the Civil War. Perry spoke publicly against that license plate, saying it would only scrape old wounds. Texas fought on the side of the South in the war.

The Sons of Confederate Veterans, which requested the Confederate license plate, filed suit against the state this week over rejection of the proposal.

Jonathan Saenz, the Director of Legislative Affairs for the Liberty Institute, a Texas-based group which fights to 'limit government and promote Judeo-Christian values,' said critics of the religious plate are "Christian bashing."

He said there are already several specialty license plates which feature Christian crosses. In 2007, the Texas Legislature agreed to insert the phrase "One State Under God," the same phrase that is on the plate, into the Pledge to the Texas Flag which is said by school students every day, he said.

"This is a matter of individual free speech, freedom of choice," Saenz said, adding that he would not oppose a state license plate which bore those words and featured a Jewish Star of David, the Islamic Crescent, or other non-Christian symbols.

"There is no requirement that you agree with every specialty license plate there is. There are people who don't like the Boy Scouts, they have a plate. There are people who don't like the Knights of Columbus (Catholic men's organization), they have a plate."

At least one Texas Christian minister said the plate is inappropriate.

"It is a way in which a particular religious faith is being favored, and even though it is my own, I understand that when one religion is favored by the state, it weakens the religious liberty of all of us," said The Rev. Larry Bethune, Senior Pastor of University Baptist Church in Austin and the Immediate Past President of the American Baptist Churches of the South.

(Editing by Greg McCune)