Story highlights The Marine sergeant facing discharge over political comments says he'll fight

Sgt. Gary Stein is accused of violating "good order and discipline"

His attorney says they weren't allowed to present evidence saying the discharge is improper

A hearing is scheduled for Friday

A Marine facing discharge over criticism of President Barack Obama on a Facebook page he administers will fight in military and civilian courts, his attorney said Tuesday.

A military board recommended last week that Sgt. Gary Stein be given an other-than-honorable discharge on grounds that he violated "good order and discipline" by calling Obama a liar and suggesting he would not follow some orders issued by the president, among other comments posted to his Armed Forces Tea Party Facebook page.

The board found he also violated rules limiting political conduct by service members.

"This is not just a First Amendment case," attorney Gary Kreep said on CNN Tuesday. "They violated their own rules, they violated their own procedures."

Kreep, executive director of the U.S. Justice Foundation, said the panel did not allow Stein's attorneys to present testimony from expert witnesses who would have said that the rule under which the board was recommending Stein's discharge only applies to commissioned officers.

Stein said the case against him was weak.

"They based this on personal opinion, nothing about the legal aspects," he said.

The case is now in the hands of Brig. Gen. Daniel Yoo, commander of the Marine Corps Recruit Depot in San Diego, where Stein is stationed. It will be up to Yoo to decide whether the discharge effort proceeds.

Stein is asking a federal judge in San Diego to block the discharge proceeding, saying it violates his rights to free speech and due process. A hearing is scheduled for Friday, but Kreep said he is not optimistic.

"The federal judge hearing this matter has expressed a marked unwillingness to protect the rights of Sgt. Stein and has urged us to go up to the 9th Circuit. And on Monday or so, if we lose on Friday, on Monday we'll be before the 9th Circuit."