PHILADELPHIA -

A federal judge is mulling challenges to the use of Pennsylvania's 2001 legislative district maps in this year's elections after the state Supreme Court rejected the state's legislative redistricting plan.

Senior U.S. District Judge R. Barclay Surrick heard arguments in Philadelphia on Monday over whether this year's races can be held under the old maps.

Last month, the Supreme Court rejected the proposed 2012 redistricting plan. A justice said in an opinion filed Friday that he believed this year's elections, including the April 24 primary, will have to be held under the decade-old maps.

Lawyers for Pa. Sen. Majority Leader Dominic Pileggi, R-Delaware Co., however, are seeking an injunction to prevent the use of the 2001 maps in elections this year, citing population shifts over the past decade.

One of the big changes brought about by the 2011 redistricting involves relocating Pennsylvania's 5th House District from Erie County to central Berks County. A few candidates have already launched their campaigns for the seat.

Surrick did not indicate when he would rule.