NEWARK, N.J. — A federal appeals court in Philadelphia is scheduled to hear arguments in New Jersey Sen. Bob Menendez’s corruption case.

Menendez was charged last year with multiple counts of bribery and honest services fraud after prosecutors say he took gifts and campaign contributions from a Florida eye doctor in exchange for political favors.

Menendez has pleaded not guilty and says he and Salomon Melgen are longtime friends and that he did nothing wrong.

A key issue the judges will weigh on Monday is a Constitutional protection given to House and Senate members when they perform legislative duties.

Menendez says he was engaged in legislative activities when he met with government officials in 2011 and 2012, while prosecutors say he was lobbying on behalf of Melgen’s business interests.