The Coalition has accused the Labor-led government of unduly injecting politics in the office of the Australian Treasury by utilising its functions in conducting cost analysis of tax polices identified with the Liberal-National alliance.

The report was leaked to Fairfax Media, which published that an Abbott government would scrap tax breaks, dump the business loss carry-back scheme and levy a 1.5 per cent tax on giant firms to finance its planned paid-parental leave.

The Treasury analysis pointed to additional burden amounting to more than $17 billion for Australian businesses if the Coalition policies were implemented and an initial extra cost of $4.57 billion under a Tony Abbott prime ministership.

However, Shadow treasurer Joe Hockey branded the unsolicited costing as grossly inaccurate, which he stressed only politicised the supposedly independent office of the Treasury.

"If Treasury undertook to conduct these unsolicited costings, or subsequently released these costings to the media, then the apolitical and non-partisan nature of Treasury has been severely compromised," Mr Hockey said in a letter he sent to the Treasury secretary, Martin Parkinson.

The Coalition has lamented that circumstances surrounding the report strongly suggested that Treasurer Wayne Swan was actively involved in the undertaking and its subsequent publication.

Labor immediately picked on the report on Monday by saying that Mr Abbott would cause undue loads to local business in the first year of a Coalition government, further ballooning over the next four year of him being the prime minister.

In a statement, Mr Swan's has acknowledged on Tuesday that it released the Treasury analysis, characterising the move as "not remotely unusual."

By analysing policies that were considered as public domain, the Treasury was merely "doing its job as it did under the previous government," the statement added.

"From time to time governments of both persuasions publicise information to contribute to a more fulsome debate about policies," a spokesman for Mr Swan was quoted by ABC as saying.

Instead of accusing Labor of playing politics, the statement challenged the Coalition "to prove that their massive tax grab will not smash the business community."

But Mr Abbott is convinced that prompting for economic or policy debates were not the intention of the leaked report because the costing seemed to have overlooked his very public intent of abolishing the mining and carbon taxes.

Also, Liberal frontbencher Jamie Briggs called the leaked report wrong and "a very serious issue."

The Treasury has a lot of explaining to do if only to clarify the whole matter, Mr Briggs said.

"I would hope very much that Martin Parkinson, the secretary of Treasury, has not allowed his department to become a politicised organisation giving out information to the government on policies they have not sought details of," the Australian Associated Press (AAP) reported him as saying.

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