Maverick Nationals MP George Christensen has fired a warning shot at Prime Minister Malcolm Turnbull by crossing the floor of Parliament to prevent impending cuts to penalty rates.

Mr Christensen made the rare move on Tuesday night after Labor put forward an amendment that mirrored the Nationals MP’s own private member’s bill on the issue.

Though the vote was narrowly defeated 72-73, Mr Christensen’s decision to openly defy the Coalition’s agreed policy position creates a political headache for a government with only a one-seat majority.

The opposition quickly labelled it an “embarrassing blow to the Turnbull government”.

It is the first time Mr Christensen has crossed the floor as a government MP and comes as he also mulls whether or not to rebel against his leadership to support a banking royal commission.

The Nationals MP said on Twitter that he had crossed the floor to “save penalty rates from Fair Work Commission cuts” and “unions bargaining them away in [enterprise agreements]”.

https://twitter.com/GChristensenMP/status/877089558629728256

Labor’s amendment, moved by employment spokesman Brendan O’Connor, would have overruled a recent decision by the Fair Work Commission to reduce weekend and public holiday rates for 700,000 workers in the hospitality, pharmacy, retail and fast food industries.

Brendan O’Connor says it was an embarrassing blow for the government. Photo: AAP

Under the proposed changes, the Fair Work Commission would no longer have the power to reduce penalty rates in modern awards.

However, they would have also prevented unions from bargaining away penalty rates for other pay and conditions concessions in negotiations with businesses, a controversial tactic that has seen some workers have their pay cut.

Mr O’Connor said although Labor was not entirely convinced by the changes, stopping penalty rates cuts was the opposition’s main priority.

“Although there are major deficiencies with the Member for Dawson’s Bill, Labor’s priority is always to put workers first and go above and beyond to protect penalty rates,” he said.

“We therefore moved to bring on an amendment which would give effect to the Member for Dawson’s Bill.”

Mr Christensen’s vote follows a targeted union campaign in his electorate over penalty rates, which has seen the Queensland MP slowly shift his position.

He recently unveiled a private member’s bill to prevent cuts to weekend rates. which was co-sponsored by Nick Xenophon Team MP Rebekah Sharkie.

Mr Christensen told the ABC he supported Labor’s amendment because it was “my private members bill pretty much word for word”.

“I was happy to cast my vote for the amendment putting to rest all those claims my bill was a stunt,” he said.

“My bill sought to protect penalty rates, but also have a level playing field between small business and big business.”

Ms Sharkie also voted for the Labor amendment on Tuesday night.

In order to bring on a vote against the Coalition’s will, Labor attempted to amend a government bill aimed at abolishing compulsory four yearly reviews of modern awards.

The parliamentary tactic was opposed by the government, but Speaker Tony Smith sided with Labor in allowing the move.

Mr Christensen had earlier abstained when Labor moved its preferred amendment, which did not restrict unions bargaining away penalty rates for other pay and conditions.

That vote was lost 71-73.

Reductions to penalty rates are due to come into effect from July 1.