MANILA — Thousands of members of a powerful Philippine religious sect rallied in Manila today, snarling traffic as they protested the expected arrest of a senator and church member.

The rally came a day after authorities announced that Senator Rodante Marcoleta, a member of the Iglesia Ni Cristo (INC) church and an ally of Vice President Sara Duterte, was set to be charged with graft tied to his election campaign fund.

The INC has historically been a powerful voting bloc with ties to the Duterte political dynasty, and Marcoleta is widely viewed as an all-but-certain vote against convicting Duterte at her Senate impeachment trial, which begins next week.

Protesters who spoke with AFP said they had been contacted by organisers at around 9:00 pm the night before via text, phone calls and messages on the Telegram platform.

“This is a lightning protest. As you know, the Iglesia ni Cristo is just one body. With just one command, everybody will follow,” 56-year-old Rodel Gundrean told AFP.

Church member Marc Raeden Quemada, 26, said he had been at the protest since 6:00 am and did not plan to leave “until we’re told to go home”.

As of 2pm (0600 GMT), traffic remained bottle-necked in the area, with police estimating a crowd of about 12,000.

“We’re expecting the number of people will still increase... so there might still be traffic tonight,” regional police spokeswoman Hazel Asilo told AFP.