An appeals court has tossed out a request by Shell Oil to block future challenges from environmental groups against Arctic drilling operations.Shell filed the lawsuit against 13 environmental and tribal organizations back in 2012. The oil company wanted a formal declaration that its government-approved spill response plans were legal. They hoped it would help them block hypothetical lawsuits down the road.But the Ninth Circuit U.S. Court of Appeals said any challenges would have to go through the Bureau of Ocean Energy Management, which approves Shell’s plans, rather than Shell itself. The court said it would be unconstitutional for Shell to determine the winner of court battles between BOEM and other groups that haven’t even happened yet.The National Resource Defense Council was one group Shell was suing. In a statement, director Chuck Clusen said, “Shell was attempting to quash dissent and circumvent due process. It didn’t work – our legal system prevailed.”The decision leaves the door open for groups like the NRDC to take potential legal action against Shell’s prospects in the Arctic. That’s as the company tries to secure more federal approvals for a 2015 drilling season in the Chukchi Sea.