Complex sentence: The Jedi Council is troubled by Palpatine's power and fears he will not relinquish it when the Clone Wars end--suspicions which only grow when the Senate grants Palpatine a vote on the Jedi Council.
Split into simpler sentences: The Jedi Council is troubled by Palpatine's power and fears he will not relinquish it when the Clone Wars end. Their suspicions only grow when the Senate grants Palpatine a vote on the Jedi Council.