An outspoken MP who fell out with Pauline Hanson’s One Nation party is warning maverick mainstay Barnaby Joyce not to jump ship.

Joyce, a former deputy prime minister, says his “less-than-spectacular” relationship with Nationals leader David Littleproud has contributed to his plan to leave the junior Coalition party, with all roads pointing to him joining One Nation.

Among the sceptics is NSW MP Rod Roberts, who aired scathing fraud allegations directed at Hanson’s party under parliamentary privilege in 2023.

“Barnaby is big enough and ugly enough to make his own decisions,” he said.

“It’ll end in tears.”

Roberts, a former veteran police officer, was elected on the One Nation ticket to the NSW upper house and said he still supported the party’s political position.

But he remains critical of its inner workings.

Among the accusations Roberts levelled in parliament was the misappropriation of NSW electoral funds by the party’s federal executive “in excess of six figures”.

“The internal governance and internal operation of the party is what stops it from progressing to become a major force in Australian politics,” the now-independent MP said.

“They never seem to be getting in a position to get their house in order … we’ve seen that happen at the state level.”

Roberts left One Nation in August 2023 after four years, saying it was acting “unlawfully and without morals”.

Hanson, who has stoked anti-Muslim and anti-Asian sentiment during her political tenure, rejected the claims at the time. She said the party’s finances in NSW and nationally were regularly audited by chartered accountants and state and federal electoral commissions.

Rumours about Joyce joining One Nation have fuelled the political news cycle. On Monday, he revealed he had spoken to Hanson.

“I did ring her last night because seeing they (the media) are talking about us, we may as well speak to each other rather than through the media,” he said.

“There was nothing locked in, nothing … let’s take it down a step.

“I have not joined One Nation.”

Kevin Anderson, the NSW Nationals MP representing Tamworth, described Joyce as a great advocate for the New England region but would not be drawn on “irreconcilable differences”.

“You’ve got a better chance of picking the winner of the 2025 Melbourne Cup than picking which way Barnaby Joyce will go,” he said.

“It’s just a wait and see on what his next moves are.”

About one in 16 NSW voters put One Nation at the top of their Senate ticket in the May federal election, matching the right-wing populist party’s vote in the 2023 state election.

But immigration debates and disaffection with the Coalition have sparked a surge in party support, according to recent polls.

The October Resolve poll found one in seven NSW voters back One Nation federally, exceeding the Queensland vote for the third month in a row.

-AAP