Liberal MP Andrew Hastie has been booted out of the Army Reserve for defying a Defence request to remove photos of him in military garb from election campaign material in the WA electorate of Canning.
Australian Defence Force members, including reservists, are banned from taking part in political activities while in uniform.
The ADF says its policy is designed to ensure the armed forces remain apolitical.
The image shows Mr Hastie in desert camouflage in Afghanistan in 2009 but also shows him holding newborn son Jonathan alongside his wife, Ruth, and is emblazoned with the slogan "not another politician".
He has not taken down the image, which was taken by troops he commanded, from posters and billboards.
"It's just a hint at, 'Hey, for the past 13 years, I've been serving in uniform' and my formative experiences as a leader were with the Australian Defence Force," Mr Hastie told 6PR radio on Thursday.
"I'm proud of that and I think it's good to let taxpayers know that their money - a lot of it has gone into my professional development - has been well spent."
Mr Hastie said the ADF had "used a bit of policy to try and push me around, basically".
"I had to decide whose authority I answered to. It was the people of Canning. As a federal parliamentarian, I don't take orders from the military.
"It's just a total beat up and I just want to get back to looking after people in Canning."
Senior Liberal colleagues backed him, with Treasurer Scott Morrison and Finance Minister Mathias Cormann saying Mr Hastie had provided distinguished service in the SAS.
"I strongly support Andrew Hastie's decision to present himself to his constituents in this election, putting forward what is part of his life history," Mr Cormann told reporters.
Australian Defence Association spokesman Neil James, however, said Mr Hastie was wrong in defying a long-held convention of non-partisanship in the military.
Mr James said it may be necessary to change the Electoral Act to prohibit the wearing of ADF uniform in all forms of election material.
Mr Morrison said Mr James was entitled to his opinion.
Fellow reservist Pat O'Neill, Labor's candidate for the LNP-held seat of Brisbane, has also knocked back ADF requests to remove images featuring him in army uniform from his political promotions.
Mr O'Neill refused to comment about the issue and whether he has also been given notice by the Army Reserve.
