A tax official repeatedly sought advice about his agency's social media rules when tweeting criticism aimed at the government, but was left unclear whether his posts were considered misconduct, internal documents show.
In emails to the Australian Taxation Office's digital and human resources branches, the mid-ranking public servant - who does not wish to be named - asked whether the tweets would break a code requiring federal bureaucrats to maintain confidence in their workplace's impartiality.
His employer at one stage in 2016 responded by declining to advise whether past tweets critical of the government were appropriate, but said the tax office would only get involved when it received a complaint or was referred to a case of suspected misconduct.
Internal emails, released under freedom of information laws and sent between April 2016 and October 2018, show the public servant's supervisor also grew frustrated at the lack of clear and specific guidance for staff wanting to express their views on social media without attracting misconduct investigations.
In seeking advice on the rules before responding to a query from the bureaucrat, a supervisor told an tax office human resources team, People Helpline, he had not seen anything published by the agency about his responsibilities as a manager in guiding staff about the Australian Public Service's social media rules.
Eventually, he responded to the public servant by describing these rules, but was unable to say whether the proposed tweet would be considered misconduct.
"Whilst I feel I do not have sufficient expertise to provide specific advice (legal or otherwise) on what is appropriate and what is not regarding social media use and each particular action that may be taken, taking into account the above points and the guide provided by People Helpline, the advice I can provide is that if it was myself in your position it would be best to err on the side of caution and refrain from making any social media comments regarding the ATO, the APS or the government," he said.
The public service's social media rules, warning against "liking" posts or making comment that could undermine faith in the bureaucracy's non-partisan role, have been the target of criticism for restricting free speech.
Internal tax office emails indicate the agency's public servants are expected to largely decide for themselves how to apply the rules - a process that in this case led to advice against making any comment about the government.
After the public servant asked his manager in September 2018 for advice about a proposed tweet calling the Morrison government a "joke", the supervisor wrote to the tax office's digital branch criticising the lack of guidance for staff trying to follow the social media rules.
The tax office had informally reprimanded staff for comments on internal networks, including Yammer, but was not supporting them in following the rules, he said.
"I am a little disappointed that there are no examples to provide a bit more idea for an employee attempting to ensure they are not potentially breaching the APS values and code of conduct," he said.
"What I am saying is that the 'monitoring' end appears quick to react by making a determination about appropriateness, but not advice upfront."
When the bureaucrat proposing the tweet said he would distribute flyers to colleagues explaining his frustration with the social media restrictions, the tax office advised him this action, and his anti-Morrison government comment, would breach the rules and could attract a misconduct investigation. Assistant commissioner Dom Sheil, from the human resources branch, also called the bureaucrat that day.
The public servant did not distribute the flyers but posted the tweet on September 30. He said his employer had not investigated him for misconduct. The tax office would not confirm the status of any inquiry for privacy reasons.
An ATO spokesman said instructions for employees, based on the public service's social media guidelines, were available to raise awareness of their obligations. The instructions included scenarios for staff to read, and the agency had published articles in employee bulletins and promoted an educational video.
"Employees are expected to exercise judgment when posting comments online including on social media," the spokesman said.
"When using social media, employees need to ensure that a reasonable person may not perceive social media statements as calling into question their ability to uphold the APS Values and Code of Conduct, specifically the need for APS employees to be apolitical."
The High Court will hear a case testing the public service's restrictions on free speech and political expression for bureaucrats, as it considers the 2013 sacking of a former Immigration Department worker for tweets criticising Australia's asylum seeker policy.