George Christensen has resigned as the Nationals chief whip, reasoning he cannot be both a rebel and an enforcer of party discipline.

He said he would not resign from the Nationals, but Thursday would be his last day as whip.

Key points: George Christensen's last day as whip will be Thursday

George Christensen's last day as whip will be Thursday He says it is so he can speak freely on policy

He says it is so he can speak freely on policy It follows a poll in his seat of Dawson which found Mr Christensen was on even footing with One Nation

Mr Christensen told the ABC he spoke with his colleagues about his decision last night, citing the need to speak freely on policy.

"I've been outspoken on a variety of topics over the last probably several months," he said.

"I just believe that the situation has probably become untenable — as the person that's supposed to be a standard bearer of discipline within the party to be out there talking against some of the Government policies as strenuously as I have been."

The fractious MP has repeatedly threatened to quit the Coalition if it did not bend to the demands of its conservative base.

Most recently, Mr Christensen penned — but did not send — a "letter of demand" to Prime Minister Malcolm Turnbull, in which he threatened to resign.

He said the decision to step down was his own, saying it eased his conscience about speaking out on issues including the banking sector and the sugar industry.

"I'm not burdened by being the standard bearer of party unity and party discipline," he said.

One Nation chasing Christensen in the polls

Mr Christensen's announcement comes one day after polling showed support for One Nation had drawn level with the LNP in his seat of Dawson.

The poll, commissioned by the left-leaning Australia Institute and conducted by ReachTEL, put One Nation and the LNP on even footing at 30 per cent and 30.4 per cent of first preference votes.

Mr Christensen told the ABC there was some threat from the anti-establishment party.

"All I can argue is that as a member of the Government, I have more influence I believe in trying to change things," he said.

Of the 863 people polled on February 20, 66 per cent supported a royal commission into Australian banks and financial institutions — something Mr Turnbull has repeatedly spoken against.

However, Mr Christensen has been a vocal critic of the banking sector, telling the ABC earlier this month he intended to cross the floor in support of independent MP Bob Katter's bill for a royal commission if it was put to a vote.

Last night, he told the ABC that his support for a royal commission would not be a show of no-confidence in his government.

"I support what the Government's doing with their reforms to banking," he said.

"I just think we need to go forward and to vote for a bill that the Government might not support doesn't mean that I'm against the Government."

Mr Christensen added today he did not intend to undermine the Government with his decision, saying "disunity is death in politics".