Labor left MPs and the Greens are perturbed that the shadow defence minister, Richard Marles, has supported a move for the Australian War Memorial to commemorate Operation Sovereign Borders.
Four Labor MPs have told Guardian Australia they personally rejected the plan or questioned the wisdom of Marles involving the opposition in culture wars on the sensitive topic of asylum seeker policy, and that concerns extended to Labor’s frontbench.
The Greens have said the idea diminishes the service of others, although even some in Labor left have defended the idea of commemorating all those who have served in the armed forces.
The memorial’s director, Brendan Nelson, has proposed that navy personnel who undertook activities to stop asylum seekers coming to Australia by boat, including through the controversial policy of boat turnbacks, should be commemorated as part of a $500m expansion of the memorial.
In comments to the Australian on Anzac Day, Marles said the royal Australian navy “has been asked to serve in this way by governments of both persuasions”.
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“The AWM should commemorate the contributions of all those who serve in our defence forces,” he said.
The Labor senator Lisa Singh said “on the face of it this proposal seems odd”.
“It’s called the ‘War Memorial’ for a reason,” she said. “Ultimately however, this should not be a decision for politicians but for the War Memorial’s council. Why not just leave it to them to make the call?”
Marles’ endorsement goes further than even the prime minister, Malcolm Turnbull, and defence minister Marise Payne, who have not commented on or approved the plan.
A Labor left source told Guardian Australia that senior colleagues were confused about why Marles made an intervention at all.
“Why would a Labor frontbencher be kicking along this shameless attempt at culture wars, particularly at a time the party is trying to work through our own policy processes? It’s hard to see how this is helpful.”
The last federal Labor conference in 2015 was the scene of an emotional debate on the floor about asylum boat turnbacks. A motion to end turnbacks, supported by a number of current frontbenchers, was defeated.
In March Bill Shorten said he had “no interest” in changing Labor’s stance on asylum boat turnbacks but acknowledged there would be a debate at the next conference, where Labor left intends to relitigate the issue and seek an increase in the refugee quota.
The Greens leader, Richard Di Natale, said the AWM proposal “diminishes all those Australians who have served and died in war”.
“By equating the personal sacrifice of the Anzacs with this government’s heartless treatment of innocent people seeking asylum, this proposal seeks to politicise Australia’s armed forces for political gain,” he said.
The Greens defence and veterans affairs spokesman, Peter Whish-Wilson, said the proposal went against existing policy at the national site, which is there to “commemorate war, not every action of the military”.
“It’s worth noting that Brendan Nelson has previously refused to commemorate the frontier wars at the AWM because it didn’t meet his threshold for a declared war or conflict,” he said.
The Labor MP Julian Hill said: “People who serve in the military serve the government of the day.
“That necessarily includes serving in missions which are wrong because the government may have done the wrong thing – Vietnam being the archetypal example,” he said.
Hill said Australia and the United States had had debates about recognition of people who served in Vietnam and had “made their peace with that”.
“It’s a lesson we should remember: that we respect their service, even while we vigorously disagree with the mission assigned.”