With the minister unmoved and Mr Miziner's local member, Labor's Tanya Plibersek, also declining to write a letter of support, the 55-year-old Sydneysider says he will be voting Greens at the federal election on Saturday, should he be strong enough to get to a polling booth.

Mr Miziner intends to not eat or drink "until I get justice".

"I don't believe it is right for me to be ignored and I don't believe I am wrong," he said.

Even sleeping in his car near Parliament House as temperatures have dipped to close to minus 8 degrees, Mr Miziner said the only person who has shown any interest in his cause was Greens candidate for Canberra, Patricia Cahill, who has checked in on him every day and tweeted Mr Dutton to review the case.

While Parliament House is largely bereft of politicians and media at the tail end of the federal election campaign, Mr Miziner said he wanted to protest there as it was a symbol of democracy. He believed he was being denied his human rights - to marry the person he loved.

"I am absolutely genuine and, frankly, if my being here and putting my life in danger is not proof I am genuine, I don't know what is," he said.

The prospective marriage visa allows people to come to Australia to marry their prospective spouse. It is a temporary visa for nine months and allows the holder to then apply for a partner visa, another step towards permanent residency.

Originally from Russia but now an Australian citizen, Mr Miziner said he met his now-fiancee, Xu Suping, at a dinner in Sydney through a mutual friend when she was visiting the country in October, 2013.

"Somehow we clicked and when she left we would call and email each other," he said.

He said he had since visited her six times in Hong Kong for about a month a time.

The couple wanted to marry but their application for a prospective marriage visa had been knocked back by both the Immigration Department and a review tribunal. Mr Miziner said he understood people took advantage of the system, breaking up as soon as the foreign partner was granted permanent residency.

However, Mr Miziner, who has been married three times before, said his love for Ms Xu was genuine.

He said the system was flawed because it was based on assumptions and could not truly determine that someone's intentions were real or not.

"How can you judge what I think?" he said.

Mr Miziner said he could go to Hong Kong and marry his fiancee there but believed the process to get her a visa could take two years. He said he was a carer for his elderly, frail mother in Sydney and could not leave her for that long. Other family were caring for her while he was in Canberra.

"I shouldn't be in a position to choose between my mother and the woman I love," he said.

Ms Xu's daughter has also been studying in Australia, including in Canberra. Ms Xu, 41, had sold a seafood business in Hong Kong and was now studying English there, Mr Miziner said.

Mr Dutton's office did not want to comment but it did back a response from a spokesperson from the Department of Immigration and Border Protection.

"Ms Xu's case has been comprehensively assessed both by the Department and a merits review tribunal. Ms Xu has been found to not meet the requirements for an offshore visa," the spokesperson said.

"Ms Xu's request for ministerial intervention has been unsuccessful after consideration of the circumstances of her case.

"The minister's public interest powers are intended for unique or exceptional circumstances only. Many requests are received each year and a relatively small number of visas are granted where a minister decides that it is in the public interest to do so."

A spokesman for Ms Plibersek said her office did want to help Mr Miziner and had offered to review his case should he provide appropriate documentation.

A petition has been started on change.org to be sent to Mr Dutton and Mr Miziner, with the help of a supporter, is also posting daily updates on YouTube.