SAN DIEGO >> A Marine sergeant who started a Facebook group that is openly critical of President Barack Obama and posted comments saying he will not follow the unlawful orders of the commander in chief is facing possible dismissal from the Corps.

The Marines on Wednesday told Sgt. Gary Stein — a Camp Pendleton Marine who started the Facebook page called Armed Forces Tea Party — that he is in violation of Pentagon policy barring troops from political activities.

Stein, a nine-year member of the Corps, said he started the page to encourage fellow service members to exercise their free speech rights. He has also criticized Defense Secretary Leon Panetta for his comments on Syria.

The Marine Corps said in a statement that Stein’s commanding officer ordered a preliminary inquiry on March 8 after receiving allegations that Stein posted the political statements violating the Pentagon’s directives.

"After reviewing the findings of the preliminary inquiry, the commander decided to address the allegations through administrative action," the Corps said.

"I’m completely shocked that this is happening," Stein said. "I’ve done nothing wrong. I’ve only stated what our oath states that I will defend the constitution and that I will not follow unlawful orders. If that’s a crime, what is America coming to?"

Stein said he planned to fight the charges. He had applied to extend his service, which was set to expire in a few months.

Stein said in addition to being discharged, he would have his rank reduced to lance corporal if he is proven to be in violation. He said he was removed from his job at the Marine Corps Recruiting Depot in San Diego on Wednesday and given a desk job with no access to computers.

According to Pentagon directives, military personnel in uniform cannot sponsor a political club; participate in any TV or radio program or group discussion that advocates for or against a political party, candidate or cause; or speak at any event promoting a political movement. Commissioned officers also may not use contemptuous words against senior officials, including the defense secretary or the president.

Stein was first cautioned by his superiors at Camp Pendleton in 2010, after he launched his Facebook page and criticized Obama’s health care overhaul. Stein volunteered to take down the page while he reviewed the rules at the request of his superiors.

He said he determined he was not in violation and relaunched the page. Last week, he said his superiors told him he could not use social media sites on government computers after he posted the message stating he would not follow the president’s unlawful orders.

Stein said his statement was part of an online debate about NATO allowing U.S. troops to be tried for the Quran burnings in Afghanistan.

In that context, he said, he was stating that he would not follow orders from the president if those orders included detaining U.S. citizens, disarming them or doing anything else that he believes would violate their constitutional rights.

Another Marine alerted his command about the statement, Stein said.

Stein said he respects the office of the president, but he does not agree with Obama’s policies. He said he is within his rights to speak up.

The Marine Corps said Stein is allowed to express his personal opinions as long as they do not give the impression he is speaking in his official capacity as a Marine.