Canning MP Andrew Hastie is defying "orders" from the Australian Defence Force (ADF) to remove photos of himself in uniform from federal election campaign material.
Mr Hastie, who was an SAS officer before being elected to parliament last year, retired from the military in August prior to taking office.
He received the ADF orders after Labor's candidate for the seat of Brisbane, Pat O'Neill, was instructed by the ADF to take down photographs of himself in uniform used in campaign advertisements on a billboard.
It is understood Mr Hastie was also threatened with disciplinary action if he failed to comply with the letter.
But Mr Hastie is standing firm and has told the ADF he won't be changing any of his campaign material.
"Before standing for parliament I had to resign from the Australian Defence Force in accordance with section 44 of the Australian constitution," Mr Hastie said.
"I am no longer under ADF authority.
"As a member of parliament, I answer only to the people of Canning."
Mr Hastie also said he would be supporting Mr O'Neill.
"I know Pat O'Neill well, I served with him for several years in Darwin at the 2nd Cavalry Regiment," he said.
"We've come up through the same institutions, the Australian Defence Academy and the Royal Military College Duntroon.
"The Australian Defence Force reflects Australian society and so you have different voices within the military.
"Pat and I have very different political world views and we've had many heated political discussions during our time in the military, but I think it says a lot of the strength of the ADF that it can produce two army officers that fall into different political camps, but who were happy to serve and fight alongside each other."
Mr Hastie said it was important for voters to know about the backgrounds of candidates if they were to make informed decisions at the coming federal election.
"Both Pat and I had formative experiences in the ADF and my photo reflects that, and voters need to know that this is my background," he said.
"Where do we draw the line? Should I not wear medals on Anzac Day while I'm undertaking official duties?"
The photo of Mr Hastie in uniform has been used throughout his election material and also includes a photograph of his wife, Ruth, and son, Jonathan.
"The real issue with the posters is the size of Jonathan, who will have gone through two elections before he turns one," Mr Hastie said.
A spokesperson from Defence said Mr Hastie did not seek "endorsement for advertising material".
"As a condition of their service, regular and reserve members of the Australian Defence Force are obliged to comply with various Defence instructions and policies," they said.
"Defence policy is designed to ensure that the ADF remains apolitical.
"ADF members are therefore not permitted to participate in any political activity in uniform, unless they are pre-approved to do so by an appropriate authority."
