At a press conference, the Mamamayan Kabalikat sa Bansa (Makabansa) and the Alyansa ng Sambayanan para sa Pagbabago (ASAP) said the administration could "manipulate" the elections if the poll body returns to the manual system of counting votes.
Ernesto Arellano, ASAP chairman, said the pro-administration party stands to benefit most if votes are counted by hand because it has the machinery and the resources.
"The polls are a few months away, and as we have observed, the Comelec is pressed for time to come up with a well-executed preparation for the organized handling of the May 10 polls," he said.
"We call on the Filipino electorate, especially those who believe that we should go high-tech, to take a hard look at this issue and join us in our campaign for automated counting."
Cyril Manaog of Makabansa said the Supreme Court "went out of bounds" when it passed judgment on the Comelec’s decision to procure the counting machines.
The poll body has filed a motion for reconsideration.