During the protracted negotiations over whether the independents would side with Tony Abbott or Julia Gillard after the 2010 election, Medibank Private helped bring Abbott unstuck.

He had gone into the campaign promising to sell it. He had prepared his costings on the basis that the resulting interest savings on government debt would boost his bottom line.

His treasury and finance spokesmen, Joe Hockey and Andrew Robb, released the costings late on a Wednesday, and three days later Australia voted, without a chance to forensically examine them.

But not to worry, Hockey and Robb had hired a team of Perth accountants to go over the numbers.

"You know what, if the fifth-biggest accounting firm in Australia signs off on our numbers it is a brave person to start saying there are accounting tricks,” Hockey said. “I tell you it is audited. This is an audited statement.”

It wasn’t.  Documents tendered in a Institute of Chartered Accountants disciplinary hearing revealed the Coalition had hired them to do work primarily “not of an audit nature”.

And as the weeks dragged on after the election a treasury analysis presented to the independents uncovered errors.

One related to Medibank Private. It was indeed legitimate to count as a budget benefit the savings on interest payments that would result from the sale. But it hadn’t also counted the offsetting cost of the dividend payments the budget would also receive.

After receiving the treasury report (and doubtless considering a good many other matters) the independents went with Labor. Tony Abbott had to wait another three years.

The government might get $4 billion from selling Medibank Private, but it won’t much move the so-called underlying cash balance. The interest savings on $4 billion or so of government debt will move the balance in one direction, the lost dividends will move it in another. On balance it’ll be a small positive.

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