Nationals renegade George Christensen has baulked and withdrawn a threat to cross the floor on an amended bill to reverse the cuts to Sunday penalty rates. He then voted with the government to adjourn any further debate until next year.

The amendments passed the Senate on Monday and Labor was hoping to enlist the support of Mr Christensen to pass it through the lower house this week where the government is currently in minority. It has 73 MPs on the floor and Labor and the crossbench have a combined 74. But independent Cathy McGowan does not support the revocation of penalty rate cuts, making Mr Christensen's support necessary for the bill to pass.

Mr Christensen was one of two Nationals MPs who were prepared to cross the floor to support a private members to establish a commission of inquiry into the banks. This forced the government to surrender and agree to a royal commission.

George Christensen was one of two Nationals MPs who were prepared to cross the floor to support a private members to establish a commission of inquiry into the banks. Alex Ellinghausen

On the weekend, Mr Christensen withdrew a threat to quit the party if Malcolm Turnbull remained leader. Revelations of his plan to bring down Mr Turnbull caused considerable anger with colleagues.

On Monday, he baulked at crossing the floor on penalty rates, claiming the amended bill did not guard employers from having to backpay workers, even though the author of the amendments, Labor Senator Doug Cameron, said it does, and the legislation makes it clear the changes will be prospective.