Tony Abbott is under pressure to reshuffle his ministry and press the reset button on controversial budget measures after a series of own-goals in the last days of the parliamentary year.
A day after Defence Minister David Johnston told parliament that he wouldn't trust government-owned shipbuilder ASC to build a canoe, sparking outrage from coalition colleagues as well as Labor members, the defence minister came into the Senate chamber to express his regret.
"Regrettably, in rhetorical flourish, I did express my frustrations in the past performance of ASC," he said.
The prime minister told parliament the West Australian-based minister was doing an outstanding job and had his full confidence.
"This minister does not deserve to be undermined by members opposite just because of a slip of a tongue," Mr Abbott said.
South Australian Liberal leader Steve Marshall said Senator Johnston's position was untenable unless he could rebuild the workforce's confidence.
The incident enhanced speculation of a reshuffle, which was already a possibility given Arthur Sinodinos remains stood aside as assistant treasurer pending the result of a NSW corruption inquiry.
Labor described Senator Johnston as being "on life support" and sought to censure him in the lower house and Senate.
"(It's) a shocking insult to thousands of Australian men and women working at the ASC," Opposition Leader Bill Shorten said.
The prime minister turned the attack on Mr Shorten, accusing the former Labor minister of leaving the country with a fiscal disaster which could only be fixed by cutting spending on such things as the ABC and finding more efficient ways to spend Defence money.
Having told the coalition party room he would be removing "one or two barnacles" by the year's end, Mr Abbott joked: "I reckon what we need to lose is Barnacle Bill."
Mr Shorten told the National Press Club the prime minister had demonstrated his "unsuitability for the job" over the past 15 months, most notably during the G20 summit.
"You cannot govern today without a vision for tomorrow," he said.
The government needed to dump its $7 GP co-payment, paid parental leave and university fee deregulation and restore rises in the superannuation guarantee.
It is understood the GP co-payment is under review and the university overhaul is the subject of talks with Senate crossbenchers.
But the prime minister remains firmly committed to the leave scheme.
Liberal Democrats senator David Leyonhjelm shed some insight into Mr Abbott's mood when telling reporters of a meeting with the prime minister where they discussed a bill to legalise same-sex marriage.
"His argument was the government's got plenty of troubles without this one coming along," Senator Leyonhjelm said.
