The plan was due to be discussed at Monday's cabinet meeting with an announcement tipped once Coalition MPs are briefed as part of Mr Abbott's new "inclusive" approach to government.

The meeting was expected to feature a "political" discussion by senior ministers without bureaucrats or advisers present.

The boost - which risks being branded as mission creep - follows last week's unexpected announcement by New Zealand Prime Minister John Key of some 143 New Zealand military personnel to be installed in Iraq in a joint deployment with Australia.

The training force is expected to be between 200 and 300 Australian soldiers and will be deployed by the middle of the year.

Senior sources have told Fairfax Media that the training force would gradually be rotated with the current deployment of about 200 special forces soldiers who are advising and assisting the Iraqis. While the overall number of Australians on the ground in Iraq will rise for a period, by the end of the year it will not be significantly higher than it is now, Fairfax Media understands.

The transition reflects the fact that the mission is expected to evolve over the course of the year from the more acute job of rebuilding the Iraqi forces to get back out and fight after their demoralising defeats last year at the hands of the Islamic State, to a longer-term training role.

The training force will remain "behind the wire" on bases and will not go out onto the battlefield, Fairfax Media has been told. Unlike the "advise and assist" deployment, it is likely to be made up of regular infantry troops rather than special forces.

With leadership speculation in Canberra quietened by a Fairfax-Ipsos poll showing the government gaining on Labor at 49-51, Mr Abbott's supporters have urged agitators to fall into line. They say unity is needed to allow the Prime Minister to focus on the deployment as well as a national security bill on compulsory metadata retention by telecommunications companies also tipped for this week, and a possible abandonment of the unpopular GP co-payment once and for all.

Also due this week is the Treasury's fourth Intergenerational Report on Thursday, which will be used by the government to reboot its flagging budget repair narrative by highlighting the trajectory of net debt growth as a proportion of GDP.

The opposition believes the report has been politicised, alleging that Treasurer Joe Hockey will show cost projections under "Labor settings" and that he has asked for the minimum population projections from departments to maximise the scale of projected debt per head of population over the next four decades.

In Parliament, Labor's Chris Bowen asked Mr Hockey if the "net overseas migration numbers underpinning the Intergenerational Report match the advice that was provided to the government by the Department of Immigration?"

"We will release a number that is larger than what Labor had in its last Intergenerational Report," he responded.

Coincidentally Labor added to its relatively bare policy cupboard on Sunday with a proposal to limit the amount of debt to equity that companies can book in Australia to reduce their taxable income.

While Labor says that, and related scrutiny measures, would return $1.9 billion over four years, Mr Hockey slammed the idea as counterproductive. He warned that multinationals would stop lending internally to fund expansion in Australia, thus costing potentially thousands of jobs in Australia.

While the Abbott government was more upbeat in the wake of the poll which had a clear stabilising effect on Mr Abbott's leadership, not everything went its way on Monday with Attorney-General George Brandis censured by the Senate over his handling of the Human Rights Commission president Gillian Triggs.

Senator Brandis was described by the Senate as being "unfit to hold the office of Attorney-General" over his strong criticism of Professor Triggs' professionalism.

Rodger Shanahan, a former Army officer now with the Lowy Institute, said the imminent training mission reflected that fact that, several months into the campaign against the Islamic State, the Coalition had a clearer picture of what was needed.

"It's the natural way of things … Planning can be imprecise early on and it gets more precise the longer you go on. So they've been able to get a better idea of the requirements of the Iraqi military."

Dr Shanahan said the campaign by the US-led coalition appeared to be going to plan.

"The Americans have got this right, unlike 2003 when they got it wrong on pretty much every level … They're addressing a complex issue quite well at the moment."

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