Senator Dave Sharma has called for consequences for federal public servants who signed an open letter that called for an end to military exports from Australia to Israel.
Mr Sharma has asked departments via Questions on Notice for their actions in response to the open letter, which as of August 6 had over 2000 signatories.
So far, more than half a dozen have responded, and taken a range of positions on what consequences, if any, signing the open letter will have for their staff.
Of the departments that have responded, the Infrastructure Department has identified 10 staff who have signed the letter, the largest number of any department.
The only department that confirmed it was taking action on those who signed the letter is the Department of Agriculture, which identified three staff. In its response to Mr Sharma's question, the department said the integrity branch was investigating, and confirmed it believed signing the letter was a breach of the APS Code of Conduct.
In its response, the Department of Health confirmed it was not taking action against any of the four employees who signed the letter.
Other departments either reiterated the Australian Public Service Commission's (APSC) social media guidance that was sent to department heads after the open letter was published or declined to comment on specific cases.
Mr Sharma said he was particularly concerned if staff at Home Affairs, Defence and his former colleagues at the Department of Foreign Affairs had signed the letter.
Home Affairs confirmed four staff had signed, while Defence and the Department of Foreign Affairs were yet to respond.
While he said staff did not need to be fired, Mr Sharma did say there needed to be "some level of consequence".
"A decision should be left to the secretary, I'm not calling for any specific remedy, but it needs to be more than reminding staff of their obligations," he said.
"We need to send a message that this sort of behaviour is not acceptable."
A spokesperson for CPSU for Palestine which endorsed the open letter said APS staff would not be intimidated.
"Efforts to silence us have actually inspired more people to speak out," the spokesperson said.
"Discussions about breaching social media policies have triggered wider discussions among APS rank and file about the genocide in Gaza."
The guidance published by the APSC states that APS employees have a right to personal and political expression on social media. This right must be balanced with the obligations of their employment, and the need to be seen as "trusted and impartial public servants".
Mr Sharma said the letter's tone was "extreme" and this placed it in a category of high risk online activity.
"These people are completely at odds with government policy," he said.
When the letter was originally circulated, the national secretary of the CPSU Melissa Donnelly said the CPSU "affirms the rights of all members to participate in political activities and protests".
The CPSU for Palestine spokesperson said punishing staff who exercised their right to free expression would send a chill through the APS.
"It doesn't take a genius to understand the dangers of having a government workforce made up of people who just follow orders and who are not allowed to speak up. You also don't inspire social cohesion by penalising voices of those who offer frank and fearless advice."
