Malcolm Turnbull is facing a perfect storm in coming weeks with unhappiness in the party room over the dropping of "big "C" conservatives threatening to boil over.

Malcolm Turnbull is facing a perfect storm in coming weeks with unhappiness in the party room over the dropping of "big "C" conservatives threatening to boil over, a difficult mini-budget pencilled in for October to facilitate tough policy changes, and strong criticism from the Productivity Commission over the Coalition's failure to undertake economic policy renewal.

His week-old prime ministership could also be dragged into tensions within the Coalition's junior partner the Nationals, with leadership aspirant Barnaby Joyce being criticised by those loyal to leader Warren Truss for causing disunity in his quest for the top job.

With allegations flying about, pro-Truss forces admit the 66-year-old leader is considering his position and could stand down early next year, but they say Mr Joyce has "misread" the party room if he thinks he can force the pace.

According to one Nationals source, Mr Joyce was telephoned by Mr Turnbull on the Sunday evening before the leadership challenge, and had given the plan "two thumbs up". Mr Joyce denied he gave the plan such an endorsement.

Fairfax Media understands Mr Turnbull and new Treasurer Scott Morrison are planning to bring forward the Mid-Year Fiscal and Economic Outlook from its usual December release to reset key policy directions, with education and taxation among the areas set for change.

News of that comes as the head of the independent Productivity Commission lashes the Coalition for failing to respond to reports it commissioned up to two years ago.

Just one day after his widely praised reshuffle of the ministry, the new Prime Minister is also being criticised by disgruntled right-wing Liberals who say the reshuffle was a case of winner takes all and resembled more of a hostile company raid than the merit-based renewal it was presented as.

"This is a corporate takeover, that's what this is," said one minister, in a veiled reference to Mr Turnbull's entrepreneurial past.

Critics say Mr Turnbull has rewarded those who switched from Mr Abbott with particular bitterness directed to the right-aligned Michaelia Cash, who was promoted to cabinet as Employment Minister.

The source predicted Mr Turnbull would now set about changes in policy via the cabinet process but would face little resistance for his "liberal" agenda because he had "stacked the cabinet".

Some of those changes may already be under way with reports the Clean Energy Finance Corporation and the Australian Renewable Energy Agency are to be transferred to the control of the Environment Minister - a sign that their proposed abolition under Mr Abbott is now off.

And Mr Turnbull has left the door open on other policies too, suggesting emissions cuts and Direct Action would be examined if they were not working as well as expected, and that tax policies were also being constantly looked at.

"There are many levers in the tax system, many possible combinations of measures, and it's important that we look at all of them," he told the ABC's AM program.

As the government re-aligns under new management, the after-shocks of last week's tumultuous events continue to be felt. The impending resignation of Joe Hockey from his seat of North Sydney will cause one byelection just weeks after the completion of another in Canning last weekend.

And Mr Turnbull could be faced with another - possibly simultaneously - in the adjoining seat of Warringah held by former prime minister Tony Abbott. Mr Abbott has so far kept his own counsel, leaving colleagues unable to say what he will do.

But his departure from office has not protected him from criticism.

Productivity Commission chairman Peter Harris will tell a competition summit on Tuesday that two years after launching what it said would be the most comprehensive review in two decades the government has done nothing about competition policy despite "occasionally reported sightings".

The 550-page Harper review cost $3 million and was delivered to the government in March.

"For too long now, under governments of both political persuasions, major reports seem to be left to languish if they no longer suit the immediate political agenda," Mr Harris will say.

"An issue here or there may selectively be picked off, but the outcome is minimal change despite the initial promise."

"Reports like Harper, or closer to home my organisation's report on Justice in Australia, now 12 months old, deserve a serious response, even if it is to reject, but explained with logic and thoughtfulness."

"The issues involved in these reports are not second order. They are social or economic first order matters."

The Murray inquiry into Australia's financial system was delivered to the Abbott government last December. It wasn't put on the agenda of the Abbott cabinet until last Monday, at a meeting set down for the night Mr Abbott was deposed. The new Treasurer Scott Morrison and the new Assistant Treasurer Kelly O'Dwyer want to delay responding to the report again while they get up to speed.

Mr Harris says that at least the Council of Australian Governments noted the Harper Review, but "it is rare to recover bureaucratically from the fate of being noted by COAG".

Mr Harris will say there is massive scope for the Turnbull government to benefit from taking up the sort of reforms suggested by the review.

The government's changes have also prompted corresponding moves in the opposition with former ACT chief minister Katy Gallagher, set for frontbench promotion along with Queensland rising stars Jim Chalmers and Terri Butler.

With David Wroe

The story Turbulent times ahead despite Malcolm Turnbull's strong start first appeared on The Sydney Morning Herald.