An officer on Australia’s flagship Antarctic icebreaker, the Aurora Australis, was asked by bosses to remove a social media post showing her on deck with a banner critical of Scott Morrison’s climate policies after Australia’s Antarctic Division contacted her employer.

Madeleine Habib, currently in Antarctica, unfurled the banner with the words “Scomo – Coal or Ice?” and posted the picture on her Facebook page.

Habib was asked to remove the post on Monday after her employer, P&O Maritime, was contacted by the government’s Australian Antarctic Division, which contracts the ship.

AAD confirmed it had contacted P&O Maritime “to advise them of a social media post” but said “no specific request” was made about what the company should do.

In commentary accompanying the picture, Habib wrote: “Here on Australia’s only icebreaker, I send a message to the Australian government. The choice is clear – end dependence on fossil fuels or face Climate Catastrophe, ‘Coal or Ice’.”

In a reply to her post, Habib wrote: “I have been instructed to remove this post. But I am not a Quiet Australian!”

Speaking to Guardian Australia from the ship, Habib said she had worked on the ship since 2006 but had a “long history” as an activist. The photograph was taken on 10 February and posted on her Facebook and Instagram pages the same day.

She said: “In the last few years I have become overwhelmed with the climate crisis and it is my intention to dedicate myself to climate activism, even if that means losing my job.”

She said she was responsible for “driving the ship and for the safety equipment on board”.

She said she had deleted the post when asked, but had encouraged others to share it. “By removing it, this has started a groundswell of support and now many, many more people have shared the message.”

In emails seen by Guardian Australia, on 17 February an AAD manager sent an image of Habib’s post to a P&A Maritime officer with the letters “FYI.”

A P&O representative wrote in an email that “social media advertisements” needed prior approval, and that it was “important that Madeleine Habib, removes the post containing the mention of our Asset & photo in the background immediately”.

Habib said she was disappointed to be asked to remove the post, “given that Australia is at the forefront of experiencing the impacts of climate change and we have a government that’s recalcitrant to any type of measures and is still promoting fossil fuels as a viable form of energy for the future”.

P&O Maritime said in a statement that while it “encourage its employees to participate in causes that are important to them, we do ask employees to ensure that their personal activities do not conflict with their responsibilities to P&O Maritime Logistics, including using our assets for personal purposes.”

“POML is committed to the safety and security of our people, our assets, and the communities within which we operate,” the statement said. “We have not assessed that this employee’s activity hampers this commitment, however, we have instructed our employee to refrain from similar activities in the future as they are not compliant with our policies on personal use of company assets.”

The company said it now considers the matter resolved and no further action will be taken.

The 95-metre Aurora Australis, currently moored at Horseshoe Harbour at Australia’s Mawson station, is the country’s flagship Antarctic vessel but is on its final summer assignment.

In a statement, AAD said Habib was employed by P&O Maritime as crew and the ship was under contract to the division.

The statement said: “The Division contacted P&O Maritime to advise them of a social media post from Ms Habib, featuring a banner erected on the ship.”

Asked why AAD had contacted P&O, a spokesperson said: “AAD contacted them to bring [the social media post] to their attention as the ship is under charter to the Australian Antarctic Division. No specific request was made.”

The Aurora Australis, in operation since 1989, will carry out its final voyage for the Australian Antarctic program in March, travelling to Macquarie Island, and will be replaced later this year by the custom-built $529m RSV Nuyina.

Habib said she was currently scheduled to work on that voyage.