AUSTIN, Texas (AP) — Texas Attorney General Ken Paxton argues that criminal charges against him are unconstitutionally vague in his formal appeal to Dallas court.

His expected appeal comes two months after a lower judge refused to throw out felony indictments against the state's top prosecutor. Paxton is accused of defrauding wealthy investors in 2011, before becoming attorney general.

The Republican was indicted last summer on two counties of securities fraud and faces a potentially lengthy prison sentence if convicted. He has pleaded not guilty.

No trial date has been set, and it's unclear when the Dallas appeals court will decide if the case against Paxton should continue.

Earlier this month, state ethics regulators earlier denied giving Paxton their blessing to let political donors pay his criminal defense.