The communications minister returned the favour in the same unstinting spirit. It's not a common event. Other ministers wondered whether they'd receive the same mark of favour. The event was suggested by Abbott's chief of staff, Peta Credlin.

All in all, it was seen in the inner circle of the government as an important reconciliation between two men who've long had a tense and competitive relationship.

It was also an acknowledgement by the Prime Minister that Turnbull  was working as a committed and collegial part of the government. "He seems to be resigned to the fact that he's not going to be prime minister," one of his cabinet colleagues remarked.

Afterwards, Turnbull went to dinner with Julie Bishop together with their staffs. They chose Wild Duck, the Canberra restaurant that first came to national attention when Turnbull and Clive Palmer dined there in May.

That dinner provoked foaming-mouthed fury from some of the more febrile right-wing commentators who imagined they detected a conspiracy against Abbott. As Bishop and Turnbull entered, the maitre d' inquired: "Mr Palmer not joining you?"

While they enjoyed dinner, half a dozen other ministers in the Abbott government were having a casual chat, Scotch in hand. One of them conjured an interesting hypothetical.

The government has a split personality. Its performance on national security and foreign affairs is an asset, but its performance on the budget and economy is a liability. It's the government's big problem.

To fix the problem, make Turnbull the treasurer, was the idea.

The ministers kicked it around. On the plus side, Turnbull would reset the entire political debate and grab the nation's attention. He would give the government an opportunity to recast its controversial budget.

He would bring competence and authority to the Treasury portfolio. He has the ability to articulate a message clearly and forcefully. The change could be justified by the changing global economic circumstance – there is a looming slowdown as China falters and Europe relapses. Turnbull has been consistently polling as the most popular federal politician on either side of the aisle.

"It'd be a game changer," one minister summarised. No one disagreed with the soundness of the idea. None of the ministers, incidentally, could be described as being members of the Turnbull fan club.

On the minus? The ministers acknowledged that it will not happen. There are three reasons that nobody in the government expects to see Turnbull as treasurer, certainly not any time soon.

First, Abbott would have to dump Joe Hockey. And the prime minister is considered to be quite protective of his treasurer. The budget, moreover, is at least as much Abbott's work as Hockey's. It's too early to abandon hope. Abbott prefers to continue working towards negotiating the Senate passage of as much of the budget as possible.

Second, Abbott does not want to reshuffle his cabinet any time soon. He needs to make minor changes in the next few months. But he is not planning a major rearrangement until late next year when he assembles the team he will take to the next election.

Third, and perhaps the biggest obstacle - does Abbott have the confidence to promote Turnbull to such a prominent position, perhaps creating a rival for himself? Abbott knows that Turnbull would be competent and that he would restore confidence in the government. But what would that do to the Prime Minister's personal confidence?

" Plan A has to work," said one cabinet minister, meaning Hockey and his budget. "There is no plan B."

It turns out, however, that the idea of Turnbull in Treasury has been considered within the ranks of the government for a while. "It's been kicked around since July," confided a minister, not one of those discussing it on Tuesday evening.

"It's come up again because there's been a certain resignation in Malcolm's manner lately. It's taken enormous pressure off the PM. So people are thinking, maybe he [Abbott] could take the risk. When it's angry Malcolm or Malcolm-in-a-hurry, no, but now, people are asking, is it safe to go back in the water?"

Certainly, Turnbull hasn't been agitating for Hockey's job. It's others in the  government who are fantasising about it, like people in the desert dying of thirst seeing water in a mirage.

Hockey is immersed in the preparations for the G20 summit in Brisbane next month. The treasurer has taken a serious approach to the G20 and deserves credit for driving a serious agenda through the many levels that lead up to the summit. But the summit is a leaders' event and he will be overshadowed by his Prime Minister.

And, unless Hockey can manage a major renaissance of the substance and style of his budget and the domestic economic agenda, the G20 will not be enough to restore his stocks and the government's standing.

The bulk of the budget remains outstanding – $27 billion worth of measures the government was budgeting on remains stranded in the Senate. That is three-quarters of the $37 billion the government projected over four years.

Some progress on some of the outstanding measures is very likely, but will it be enough? The government faces a serious risk that it will make the deficit bigger, not smaller, by the end of its first term. It's failing to win its budget measures, and projected revenue is disappearing daily as the price of iron ore, coal and gold continues to slump below the budgeted levels. To deliver a bigger deficit than Labor would be a profound political failure.

The logic of blame inside the government runs like this: The Liberal Party has been seen by the electorate as having two big strengths. It's perceived to be strong on economic management and strong on national security. These are part of the party's electoral DNA.

"We are seen to be strong on national security now, but suddenly, after 70 years with economic management as a strength, we're not seen as being strong on it," says a senior figure in the government.

"We are not ahead in the polls. Why? Economic management is pulling us back. Rarely do you win elections on national security. People expect us to be solid on it. We don't get special credit. And Bill Shorten has cleverly minimised the differences on the national security agenda," closely supporting the government's deployment to Iraq and its counter-terrorism bills.

"So where are the big differences between us and Labor? It's economic management and the budget."

Hockey gets little sympathy from his cabinet colleagues. Said one: "We all have hard jobs to do. Joe just has to do his." And the Liberal backbench is quietly seething with frustration.

Until Abbott makes a serious restructuring of his cabinet, the changes will be limited to minor care and maintenance. The post of assistant treasurer remains vacant. Arthur Sinodinos stood aside while he's investigated by the NSW ICAC. Depending on ICAC's findings, Abbott will have to reinstate him or replace him.

The other pending question is whether Abbott creates a ministry of homeland security. This is the prospect which inspired much speculation this week about Scott Morrison's "land grab" or "empire building".

Abbott asked his department, the Department of the Prime Minister and Cabinet, to study the idea of reorganising some of the institutions of government to create an overarching ministry in charge of domestic security. The review is pending.

If it were to happen, it would mean that Morrison would probably be made the new minister, with an enlarged portfolio. The portfolio would not be as large as much of the speculation suggests, however.

The guesswork running in parts of the media has included Morrison taking parts of the portfolios of Foreign Affairs Minister Julie Bishop, Agriculture Minister Barnaby Joyce and Defence Minister David Johnston. None of this is correct.

A new department of homeland security would, however, logically take ASIO from Attorney-General George Brandis and the Australian Federal Police from Justice Minister Michael Keenan, and be added to Morrison's Customs and Border force and his Department of Immigration.

Morrison favours this idea. But Brandis and Keenan are opposed to it, and so are the agencies themselves, ASIO and the AFP. But the decision is Abbott's. While he thinks about it, the opposition decided to have some fun fanning the internal rivalries by raising it in question time this week. When Labor asked Morrison what expertise he has in the various areas of government that might be involved in a reorganisation, he leapt to his feet to answer. The Speaker, Bronwyn Bishop, ruled the question out of order and Morrison returned to his seat.

If he'd been permitted to answer, he probably would have made the point that his Operation Sovereign Borders involves the seamless and successful co-operation of 16 different agencies of government, most of which are not in his current portfolio.

The 16, incidentally, include two of the agencies that would, realistically, become part of any new department of homeland security – the AFP and ASIO. Subtext – I've already shown I can work effectively with the agencies a homeland security minister would manage.

Abbott's likely to reach a decision by the end of the year. In the meantime, Abbott doesn't mind the jockeying of his ministers. "He loves it," said a cabinet minister, "it helps keep everyone in line.

"Do you think John Howard lost any sleep over the tensions between Peter Costello and Peter Reith? If there weren't any, Howard would create some. If they're squabbling over each other's jobs, they're not squabbling over the leader's job."

Rapprochement on one hand and creative tension on the other, all part of the delicate business of a prime minister who intends remaining prime minister.

Peter Hartcher is the political editor.