Advocates for Pennsylvania's Latino population say they'll challenge a federal court ruling involving the state's overdue legislative redistricting plan.

Groups including Latino Justice said Monday they plan to appeal the April ruling by U.S. District Judge R. Barclay Surrick. He rejected their suit seeking a statewide special election in 2013 that would force lawmakers elected in November to serve shortened one-year terms.

Last year's legislative elections were based on district maps drawn in 2001 because the state Supreme Court rejected a special commission's plan for realigning the districts to reflect population shifts in the 2010 Census. Proposals currently before the justices would not take effect until 2014.

The Latino advocates say electing legislators based on decade-old data is unconstitutional.