Former independent senator Nick Xenophon has become the new mouthpiece of Chinese telco giant Huawei who he believes has been treated unfairly.
Mr Xenophon sees the company as "underdogs" and will be representing Huawei in the media.
He will seek to overturn the government's ban on its involvement in the 5G network.
Huawei was banned from being involved in the new network over security concerns, with the telco linked to the Chinese government.
"Huawei is fed up with this and that's why we are acting for them," Mr Xenophon said.
The company said Mr Xenophon would be part of its new "strategic counsel" to defend the company locally against reputational damage.
Prime Minister Scott Morrison said banning Huawei from the new network, and any operators that could be influenced by foreign governments, was done in Australia's national security interests.
"And we stand by it and it was not directed at any one operator," Mr Morrison told media in Canberra on Monday.
"I wish Nick all the best in his new employment and it sounds like he's prosecuting his case. It's a free country."
Huawei has been blacklisted in the United States and was also banned from joining New Zealand's 5G rollout.
Mr Xenophon left federal politics in 2017 to make a failed bid at South Australian parliament in 2018, but his Centre Alliance party holds crucial crossbench power in Canberra.
Australian Associated Press