Several weeks ago, Brendan Nelson declined to back Malcolm Turnbull when Treasury Secretary Ken Henry handed out one of the biggest don’t-argues ever dealt by a bureaucrat to a serving politician.

Turnbull had claimed that Treasury recommended a specific minimum wage increase in the Government’s submission to the Fair Pay Commission. “These claims are false,” Henry immediately said, in a rare public statement. Nelson, asked at the National Press Club whom he believed, said he preferred Henry’s version of events. Turnbull was humiliated, and it was naturally seen in the context of the Liberal leadership issue.

But today Nelson has fully signed up to Turnbull’s agenda as shadow Treasurer, arguing that there is no inflation crisis and that there is no need for cuts in government expenditure. The entire focus on inflation, Nelson reckons, is a Rudd-Swan plot to discredit the Coalition’s economic credentials.

The anxiety of the Coalition leadership to prevent damage to the Howard-Costello economic brand is motivated by a worry that, like Labor under Beazley, a successful discrediting of their economic record will make it even harder to present as a credible alternative government.

They also still hold hopes that the inflationary effects of the Government’s reversal of Workchoices can be established as a credible narrative – even though they themselves have declared Workchoices dead.

It’s clear, amidst all the mixed messages emanating from the Government, that it won’t tackle the big ticket items of Howard-Costello spending in middle-class welfare, health and defence because of Kevin Rudd’s me-tooism in 2007. So Lindsay Tanner is stuck trying to find savings at the margins. The chances of any actual reduction in government outlays next Tuesday looks minimal.

So, really, this is a fake debate. The Government and the Opposition are arguing the toss over expenditure reductions of a couple of billion dollars when neither will seriously contemplate taking the meataxe to spending that Rudd promised.