The arrest of Senator Jinggoy Estrada has deepened a political deadlock in the Philippine Senate, potentially stalling legislation and complicating impeachment trials.

The arrest of Philippine Senator Jinggoy Estrada has deepened a stand-off in the Senate, leaving the chamber split between two 11-member blocs and raising the risk of a wider political crisis, analysts told This Week in Asia. They warned the stalemate could stall legislation, delay military appointments and complicate Vice-President Sara Duterte-Carpio’s impeachment trial, leaving the Senate’s basic ability to do business hostage to a factional power struggle. Estrada, chairman of the Senate...