DENVER — Oklahoma Attorney General Scott Pruitt is trying a new tactic in his fight to have Colorado's legalization of recreational use of marijuana overturned.

Pruitt and his Nebraska counterpart are asking an appeals court to allow them to join a court case that may decide whether federal law against marijuana pre-empts Colorado's legalization.

The two attorneys general on Thursday jointly asked the 10th U.S. Circuit Court of Appeals to allow them to intervene in the case. Opponents of legalized marijuana are pursuing that case at the Denver-based appeals court.

The appeal seeks to overturn a lower court decision. It concluded the opponents had no right to sue on their claim that federal law preempts Colorado's legalization.