Mark McGowan is refusing to apologise for using imagery of his past military service in election campaign material, saying his time in the navy helped shape him for a leadership role.
The Defence Department contacted Mr McGowan’s office this week to warn the Opposition leader against using pictures of himself in uniform, saying the military must remain apolitical.
In a policy pamphlet published at the weekend, Labor used an old picture of Mr McGowan in uniform.
ADF members and reservists are banned from engaging in political campaigning in uniform for fear the military could be seen to be taking sides.
Mr McGowan served in the navy for seven years as a lawyer before leaving the service in the mid-1990s. He remains in the Defence reserves.