New guidelines from the Department of Prime Minister and Cabinet (PM&C) will urge public servants to report colleagues who post critical comments on websites such as Facebook and Twitter, whether in an official or unofficial capacity.

The rules also apply to comments made anonymously, if the person who reported the post had knowledge of the poster's identity.

Former public servant turned online engagement consultant Craig Thomler said the guidelines could be asking public servants to breach the Privacy Act by reporting private conversations in closed Facebook groups or private forums.

“There’s a thin line as to whether they’re public or private comments, because they’re occurring in a closed room,” he said.

“There’s definitely a case to say that PM&C’s policy may go too far by asking people to potentially breach the privacy of their friends.”

Privacy Commissioner Tim Pilgrim has been approached for comment.

Mr Thomler said there was little opportunity for public servants to express their opinions about the guidelines, as their comments may in fact breach the social media policy.

“It is actually a Catch-22 situation,” he said.

High profile cases

Former Immigration Department worker Michaela Banerji was sacked after she used an anonymous Twitter account to criticise the government’s refugee policies.

Posting under the pseudonym “La Legale”, Ms Banerji garnered more than 700 followers through her regular tweets criticising Australia's immigration detention policies and politicians.

In another high profile case, Department of Foreign Affairs and Trade employee Darrell Morris was suspended over his involvement in a Facebook page detailing alleged wrongdoing in the public service.

Union backlash to ‘nasty’ policy

Community and Public Sector Union national secretary Nadine Flood said the union was representing members with social media issues in the wake of the “Dob in a Mate” policy.

In a comment posted on Facebook on Monday, Ms Flood described the plan as a “new, nasty feature of the PM's Department social media policy.”

“CPSU saw an earlier draft policy without this provision and raised concerns about the rest of the policy, which is mostly based on 2012 Public Service Commission guidelines,” she said.

“We're raising it with PM&C.”

Further comment is expected from the CPSU later today.

Government deems policy ‘appropriate’

In a statement provided to SBS on Monday, a spokesman for the Department defended the policy.

“The Department considers the social media policy is appropriate. It is an internal document for employees and is consistent with APSC guidelines,” the statement read.

“The Department will make no further comment.”

Posts are in breach if they are: “harsh or extreme in their criticism of the Government, Government policies, a member of parliament from another political party, or their respective policies, that they could raise questions about the employee's capacity to work professionally, efficiently or impartially.”