Former Liberal senator Cory Bernardi joins One Nation

Former Liberal senator Cory Bernardi has become the latest politician to join One Nation as the party surges ahead in polling.

Pauline Hanson is expected to announce Bernardi would stand as the party's top upper house candidate in next month's South Australian election.

Bernardi served as a senator for almost a decade until 2020.

READ MORE: Can One Nation really upset the major parties? Why a 'reputation' test is looming for Pauline Hanson

He later quit the Liberals and formed his own party, Australian Conservatives, but it failed to make an impact with voters.

Following his departure from politics, Bernardi has been an oyster businessman and restaurateur on the Eyre Peninsula in SA.

He aims to make those experiences in the regions and running a business part of his campaign focus.

Ahead of today's announcement, Bernardi praised One Nation's progress in the polls on social media and said he would be "lending my shoulder to the ON wheel".

"I'm so happy that their time has come, and the country looks intent on changing the current course of politics," he said.

NEVER MISS A STORY: Get your breaking news and exclusive stories first by following us across all platforms.

• Download the 9NEWS App here via Apple and Google Play
• Make 9News your preferred source on Google by ticking this box here
• Sign up to our breaking newsletter here