Another threat emerges ahead of Sona
Parliament employees affiliated to Nehawu are threatening to withhold services if not granted a 13th cheque.
Hundreds of Parliamentary employees affiliated with the National Education Health and Allied Workers Union (Nehawu) are threatening to withhold their services if they aren't granted a 13th cheque, among other demands.
Parliament's presiding officers have refused to speculate on what steps will be taken should Economic Freedom Fighters (EFF) members of Parliament (MPs) disrupt proceedings inside the chamber.
There could be a volatile showdown on Thursday if EFF leader Julius Malema makes good on his threat to disrupt the president's speech.
Parliamentary staff want a 13th cheque.
They say they won't help with preparations for the president's Sona unless this is granted.
Malema says nothing has changed and the EFF will go ahead with its plan.
"There is no reason of us waiting anymore because we know this man is going to go AWOL. The best thing is to ask him questions where you find him."
At the same time, National Assembly Speaker Baleka Mbete has refused to speculate on the EFF's threat.
"At the point at which anything happens, we will deal with it as it unfolds. We will have to come to terms with it as it happens."
Mbete would not say whether public order police are being deployed, insisting that planning took place on many levels and that some of the detail were 'operational'.
WATCH: Behind the scenes at Sona
Sona in numbers.