Let us assume that I am Secretary to the Treasury. You might think that I’ve had my feet up these past few weeks during the caretaker period. Gosh, I might even have played a few rounds of golf, lowered my handicap. Maybe I should change my name to Rory Sloan.

Actually, I’ve been flat out preparing the Red and Blue Books, one of which is presented to the incoming government. I only have several hundred staff members to help me, so it’s hard work, shoulder to the wheel stuff.

Let’s recall here what the Red and Blue Books are all about. The Red Book is for an incoming Labor government; the Blue one for the Coalition. The book for the loser is quickly destroyed.

In fact, most departments prepare Red and Blue Books, but because Treasury is responsible for economic management and the budget, my brief is much wider than for the other departments.

The point is that I can stick my nose into any area that interests me; be it environmental policy or social security, be it education or defence. Like pretty much every Treasury Secretary in the past, I have an opinion on everything.

The protocol for the preparation of these books is that the broad parameters of the party’s stated policies are accepted and the advice given in the coloured books is based on making sure the policies are implementable in an effective and efficient way. I don’t have to worry too much about Freedom of Information requests because there is scope for massive redaction, but frankly I would welcome such requests because I have nothing to hide.

I’ve decided this time to break with protocol in a novel and significant way: the Red and Blue Books will be the same. Maybe I should rename it the Purple Book because mixing red with blue would yield a purplish hue.

I’m overlooking virtually all the loopy policy proposals that the two parties have announced during the campaign – they have been mainly outright pork-barrelling designed to scoop up votes – and stick with the principles of best practice policy for a small open economy facing significant global uncertainty.

Now I realise that this innovative approach may not be welcomed by the incoming Treasurer, but what the heck.  Unless someone stands up for the national interest and worries about the future, we are stuffed, rooted, up a creek without a paddle – you get my drift.

The first substantial point I will make is that government spending must return to this century’s average as percentage of GDP – around 23 per cent.  According to the budget that was handed down in March, the government expects to spend 27 per cent of GDP next financial year.

Read my lips: this is way too high. At a minimum, the incoming government will have to find savings of $200 billion-odd over four years to meet my requirement.

‘How can this be done?’ the incoming Treasurer will wail. If Paul Keating and Peter Walsh were able to achieve something similar in the late-1980s, then it is clearly possible. It is a matter of clear prioritising, of handing spending back to the states that should never have been taken over by the Commonwealth, and of cutting out wasteful program altogether.

It is letting the public know that government spending will now focus assistance on those with the lowest incomes, no longer handing out subsidies to well-heeled toffs in expensive suburbs. We need to bring back strict means-testing for government benefits. No more childcare subsidies for couples earning over half-a-million dollars annually. No more FBT exemptions for boastful purchasers of electric vehicles on novated leases.

We need to terminate the well-intentioned National Disability Insurance Scheme – there was never an insurance element to it – and start again. The NDIS Mark II will be confined to those with serious and permanent disabilities, and not cover children who are suffering minor developmental delays.

It is simply not possible to have a scheme that will cost more than Medicare, which caters for the entire population. To suggest that annual eight-per-cent growth in NDIS spending is acceptable is simply nuts.

And while I’m here, I should mention that the scheme to promote more GP bulk billing and the funding of even more unproven Urgent Care Clinics (UCCs) must both be ditched, tout de suite. It simply doesn’t make sense to spend $8 billion to achieve a marginal gain in the proportion of standard GP consultations that are ‘free’ to the patient.

And we should not press on with setting up new UCCs until we have properly evaluated the ones we already have. It might sound obvious that UCCs are taking pressure off public hospital emergency departments, but this needs to be proven. The alternative view is that by offering a new ‘free’ service, all we are doing is adding to demand and shuffling around where it is met.

Let me turn to energy and electricity prices. The idea that there can be a Future Made in Australia without affordable and reliable energy is absurd. We also cannot go on subsidising household and business electricity bills from the budget.

In other words, we must have a frank conversation about the energy transition and the possibility that renewable energy, even with storage, won’t cut it. Nuclear power may well have a place in the future, but we need to accept that coal and gas will play a central role in meeting our energy needs for the next twenty years at least.

While we are at it, consideration is required about our emissions targets and why Australia is committing to net zero by 2025 when so much of the world is essentially heading in the other direction.

We also cannot avoid the topic of the defence of the country and the need to spend more on well-targeted and effective measures. The fact is we are in a very tricky position with China our major trading partner – by a country mile – but also our major geo-strategic enemy. This makes us vulnerable at both the economic and strategic levels.

It’s not simply enough to set a target for defence spending as a proportion of GDP.  We need long-range weapons, but we particularly need a well-trained and appropriately sized defence force. We have let the army, air force and navy become too top-heavy but with the turnover in the lower ranks being unacceptably high. We also need to assess how self-reliant we are given the apparent weakening of our alliance with the United States.

I should mention here that there are separate chapters on industrial relations, tax reform, productivity, infrastructure, immigration and housing supply. There is a great deal that needs to change.

It may be that Secretary Sloan’s tenure will be limited but her message is clear: wrong way, turn back. We simply cannot continue down the path of economic policy that has been followed over the past several years: wasteful overspending, a bloated public sector, costly overregulation and a growing burden of tax. Bring on the Purple Book.