Parliament - Speaker Baleka Mbete said she would take legal advice on how five vacant seats in the National Assembly on Tuesday, would impact on the margin required for a vote of no confidence in President Jacob Zuma to pass.
Mbete confirmed that a simple majority was needed for the opposition motion to force the president's resignation to succeed. It would mean that, if all MPs were present, 201 votes in favour of the motion would mean it passed.
But questions were raised about the impact of five vacant seats, and the Speaker then said she believed regardless of this the margin for the motion to pass remained 201 votes.
She undertook to get legal advice on the matter however.
Democratic Alliance chief whip John Steenhuisen said he was not sure whether the issue could keep the outcome of the vote against Zuma hanging in the balance.
Voting of ballots began around 6pm on Tuesday evening after a fiery debate in which the opposition pleaded with ruling party MPs to flout a three-line whip to throw Zuma out of office.
DA leader Mmusi Maimane and his Economic Freedom Fighters counterpart Julius Malema tried to persuade African National Congress MPs that the motion was not a bid to dislodge the ruling party but to oust a president who had betrayed the nation, including his own movement.
More questions about procedure arose just before counting began, when the Freedom Front Plus asked Mbete whether she planned to cast a deciding vote if needed.
The Speaker said it had always been her understanding that she was only obliged to do so when the National Assembly when equal numbers of MPs had voted for and against a particular measure.
"Unless there is a need to do a casting vote when in fact there is an equal number in the house, then I would have to exercise that casting vote," she said.
Mbete on Monday announced that she would allow a secret ballot on the motion, raising opposition hopes of that a sufficient number of ANC MPs would support the motion for it to pass.
However, outside the National Assembly on Tuesday evening, many said they believed the opposition would not muster enough votes to oust the president after eight years in power.