IT WAS a government sting, and then an opposition counter-sting, which left the public servants in the federal Treasury feeling the pain.


This week's row over the department's costing of the impost on business of three Coalition policies was a textbook exercise in government spin, countered by a tough opposition fightback.


But the incident raised wider questions about the role of the public service, and, if Tony Abbott wins next year's election, what sort of relationship his government would have with the bureaucracy.


The story started on Monday, when Fairfax journalist Peter Martin reported that a Treasury analysis had found Coalition policies on parental leave and some proposed tax changes would cost business $4.57 billion in their first full year.


The story properly made the point that Treasury had not included in its exercise the opposition's plan to scrap the carbon and mining taxes, which would benefit business. As the government later admitted, it asked for the costings and released the material. But it did not at the time associate itself with the release (which was not a ''leak'' in the real meaning of that word).


To get maximum impact, it kept itself at a distance. That way, all the attention was on the fact that these were Treasury figures. It gave the material to one journalist, so the story could be labelled ''exclusive'' and get the best run. Because of the syndication of stories, the article was published in three papers.


The figures were embarrassing for the opposition, which also knew it was vulnerable to the tactic, if not called out, being frequently reused. The Coalition managed to turn the issue into one about process rather than content with shadow treasurer Joe Hockey (after Trade Minister Craig Emerson said Treasury had ''made available the results'') writing a sizzling please-explain letter to Treasury secretary Martin Parkinson.


The government had to take ownership of its role. Parkinson further drove home responsibility, writing back to Hockey, ''I appreciate your concerns'', and saying Treasury had provided the costings to Treasurer Wayne Swan at the request of his office, and did not give the material to ''anyone outside of government''.


Treasury acted properly. As Parkinson wrote, ''it has long been the case that Treasury is periodically asked by the government of the day to cost or analyse alternative policies''. Outside the ''caretaker'' period, it doesn't do unsolicited costings.


The government, by initially trying to keep its distance, did the wrong thing by its bureaucrats. But the incident, leading to Parkinson's insistence that Treasury had not breached its ''apolitical ethos'', might have served the public service well, clearing the air with the opposition.


The Coalition is coy about its preparations for government, but handling the public service is an issue.When John Howard won in 1996, he foolishly chopped a third of the departmental heads. Abbott would be unlikely to repeat that hatchet job but individual secretaries will be nervous.


A while ago, Hockey was asked about Parkinson's future. He declined to guarantee it, and some Liberal sources predicted Parkinson would be shifted. But now his position looks safer.


There would be no good reason to move Parkinson: he is a very proper public servant, and a good economist with a market-oriented approach.


Indeed, the current heads of the key departments should all be acceptable to a Coalition government. Ian Watt (Prime Minister and Cabinet) was highly respected when he worked for Nick Minchin in Finance; Peter Varghese (about to take over Foreign Affairs) has effectively served both sides; Dennis Richardson (Defence) has a top reputation across the political divide, and David Tune (Finance) is well regarded.


As a minister, Abbott was seen to have a professional relationship with the public service. There are some in the Coalition, however, who believe the bureaucracy is too left-leaning. Hopefully Abbott would not be swayed by them.


He might usefully read the observations of James Button, a former Age journalist who worked as a speechwriter for Kevin Rudd and was based in the Prime Minister's department.


In Speechless, Button writes: ''Public servants were serious about their obligation to to be apolitical. At a meeting in the PM's office I watched Ben Rimmer, a deputy secretary, carefully mark out the limits of the department's advice - 'That's for you to decide, not us' - when the PM's advisers began discussing the politics of an issue. Even casual conversations in the department had a way of discussing politics in a way that was more like commentary than endorsement. After work, out of uniform, you would hear political views, but not in the office.''


Despite pressures in recent years, including senior bureaucrats now being on contracts, pushing the system towards greater politicisation, most senior public servants do try to uphold the traditional values of frank advice and political neutrality - occasionally to their ministerial masters' discomfort.


Michelle Grattan is political editor.