Govt MP mistakenly backs ALP criticism

A Liberal backbencher has inadvertently agreed with the opposition that his government is short-changing Australian pensioners.

Scott Buchholz, a former chief whip, on Monday backed a motion by Labor MP Emma Husar criticising the coalition over the calculation of pension payments.

He was asked by Labor MP Rob Mitchell, sitting in the Speaker's chair, whether he wanted to "second the motion" - which signals support for the issue - which he did.

"I'm sorry for my loss of protocol or procedure in the house," he said.

Mr Buchholz wanted to speak on the motion because he grew up in household in Queensland where the sole source of income was a widow's pension.

It follows a similar procedural stuff-up in October, when the government effectively voted to call on itself to explain its failures on multinational tax avoidance.

In September, the opposition exploited the government's slim majority to win procedural votes on a bid to debate a call for the establishment of a royal commission into banks when a number of MPs left early.

"Gov brought forward its weekly own goal to the Monday," Labor frontbencher Tony Burke tweeted.

Mr Burke later moved a motion to, in part, jokingly "congratulate" Mr Buchholz for his willingness to condemn the Turnbull government.

The chaos in the Senate had extended to the House of Representatives, "where every week there is a new stumble", he said.

Mr Buchholz later said he only backed the motion to allow debate on it to continue and if anyone failed in their responsibility, it was the Labor seconder.

"I made clear my support of the government's policy surrounding pensioners in my speech," he told parliament.