Poll watchdog Parish Pastoral Council for Responsible Voting (PPCRV) is calling for more volunteers as it is starting its random manual audit (RMA) of election returns (ERs).

Ana de Villa-Singson on Wednesday, May 14, made the call as the church-based group already received nearly 98 percent of total ERs from across the country.

Singson said the remaining ERs that the group has yet to receive yet mainly come from the Bangsamoro Autonomous Region in Muslim Mindanao (BARMM).

She says the conduct of the RMA is important to ensure that there is no manipulation of election results during their transmission to the Commission on Elections (Comelec).

PPCRV earlier raised concern about the results after it momentarily lost its "eye" on the data of the results, particularly during the first hours of the transmission of ERs.

"The transmitted vote is most vulnerable to manipulation while it's out there being transmitted to its destination," she said in a press conference.

And now that there are more ERs coming in, Singson called for more volunteers.

"We'd like to call for volunteers already because we're being very careful about the number of volunteers we call until we have a good critical mass of ERs," she said.

PPRCV's command center in Sampaloc, Manila currently has 185 volunteers. But it could expand its capacity to up to 240 volunteers.

Most of the regions already transmitted 94 to 99 percent of their total ERs. It was only BARMM that transmitted less than 90 percent, or at 74 percent.