The first-term parliamentarian failed to sign off on the vote belonging to Julian Tan, the DAP MP for Stampin, that resulted in it not being taken into account.
This led to the opposition losing the bloc vote on the 2018 Budget allocation for the domestic trade, co-operatives and consumerism ministry.
In announcing his decision today, Manivannan said he was stepping down due to the costly mistake he had made.
“As a matter of principle, I have resigned with immediate effect and have already conveyed my resignation to PKR whip Johari Abdul,” he said in a statement.
“The omission of YB Stampin was not purposely done.
“It was a human error and I have apologised to the house, the speaker and YB Stampin, and the house has accepted it.
“I have met YB Stampin personally to convey my apology and he has accepted it,” he added.
Speaker Pandikar Amin Mulia had earlier today said although 52 opposition MPs participated in the bloc vote, the voting paper from Tan was not signed as required.
Manivannan claimed that the counting system was flawed and that this was acknowledged by Pandikar.
He said the officers of Parliament, who were supposed to assist in the calculation, failed to double-check and did not highlight any omission.
“The speaker has agreed that the counting system is flawed. I have suggested for a better counting system for the bloc vote in the future,” he said.
The provision under the Supply Bill 2018 was approved with the narrowest of margins, with 52 votes for it, 51 against it and two MPs from PAS abstaining.
Manivannan had called for the bloc vote after Domestic Trade, Co-operatives and Consumerism Minister Hamzah Zainudin wrapped up his speech on behalf of the ministry.
Ministry’s budget allocation passed by just one vote in Dewan