NEVER let a good crisis go to waste. The Brexit clusterbourach, as it is now officially known, has wiped every other issue off Scotland’s battered political consciousness. We’re all transfixed in horror at Westminster’s descent into constitutional madness. This presents an opportunity for the Scottish Finance Secretary, Derek Mackay, as he delivers his Draft Scottish Budget today. He could scrap council tax and slap a supertax on domestic pets and, right now, hardly anyone would notice.

The big issue, had it not been for the Brexit shambles, would be the Scottish Government’s expected decision not to raise the threshold for higher rate tax payers to £50,000, as announced in the UK Budget. This would normally be portrayed by the Conservatives and much of the press as an irresponsible Nat Tax increase that would “hammer middle income earners”, even though it does nothing of the kind. Embarrassingly for Labour, the Shadow Chancellor, John McDonnell, controversially supported the Tory threshold rise, which of course is an effective tax cut for higher earners.

Scots earning around £50,000 are a vociferous group and they could find themselves paying £1,300 more in income tax than they would had they been living in England. That’s serious money. However, few of the 300,000 or so higher rate payers are in a position to pay the relocation costs of fleeing to the border, even if they wanted to. And of course many won’t actually notice, since they will see no increase in their tax bills.

So, with political attention elsewhere, Mr Mackay has a unique opportunity to raise tax without actually raising taxes – the ultimate stealth tax. Just doing nothing brings a conditional windfall of more than £200 million, according to the Fraser of Allander Institute (the exact figure is hard to determine because the Barnett Formula compensates the Scottish government for notional tax losses as a result of UK fiscal policies – or, er, something like that)

The vast majority of Scots, anyway, make a lot less than £50,000. Median gross earnings are less than half that figure. Mr Mackay could fiddle around with the new rates and bands, and deliver a headline tax cut to half of Scottish workers and still be quids in. A useful little tax giveaway in what could be an election year. – though he’d be wise to avoid pulling out too many budgetary rabbits since, with the Scottish economy expected to slow down after Brexit, overall tax revenues are likely to be depressed in future.

Indeed, Mr Mackay has more than usual reason this year to be grateful for the much-maligned Barnett Formula. Thanks to Chancellor Philip Hammond’s increase in NHS spending, the Scottish Government will receive £550m for health alone next year through Barnet “consequentials”. With NHS boards like Lothian plunging into the red, this has come not a moment too soon.

As is well known, the SNP Government failed in past years to devote all the health revenue increases to the Scottish NHS. This time Mr Mackay has made clear every penny will go to health. Half a billion should at least paper over the cracks in a service which still has widespread public support, but has serious problems. Though no one should underestimate the capacity of the NHS to swallow vast amounts of public money.

With new medicines and procedures, health spending needs to rise by around two per cent just to stand still. Scotland’s population is ageing rapidly and older people need expensive care. Waiting targets in A &E are being missed. There is a recruitment crisis that is only going to get worse as doctors and nurses stop coming from Europe after Brexit. The spending watchdog, Audit Scotland, reported recently that the NHS in Scotland is “financially unsustainable”.

The injection of cash from Westminster will put this crisis off for some years. However, the sheer volume of resources devoted to the NHS is creating problems elsewhere. Nearly half of the entire Scottish budget now goes on health, and this has squeezed local government. Thanks to austerity, council spending has been cut to the bone over the last decade, and there is little prospect of them being able to catch up. Crucial services like education, social care and waste recycling are disintegrating. Teachers are threatening to go on strike if they don’t get a 10 per cent pay increase.

Council cuts can’t go on much longer without causing irreparable damage to communities. The obvious answer is to allow councils to raise more money themselves. But the Scottish Government allowed them to raise the council tax cap last year by three per cent, and it didn’t make much of a dent in the problem. Councils are also raising cash from things like parking charges and the ending of second home discounts, but more needs to be done. Many believe that only a replacement of the council tax itself, by a local income tax or land and property wealth tax, could close the gap.

The Scottish Green Party, whose six pack of MSPs are threatening to vote against today’s budget, could potentially bring down the Scottish Government over council tax reform. A firm timetable for its abolition is their green red line. But I doubt Scottish voters could cope with another parliament in crisis right now, so their co-leader Patrick Harvie will probably settle for rather less. Possibly movement towards the “transitory visitor levy”, otherwise known as the tourist tax.

It’s not entirely clear why Nicola Sturgeon is so leery of a tax that is applied in most European cities. Edinburgh hotel rates are now so high – more than £100 a night on average – that a two per cent tax would hardly be noticed, especially since foreign visitors are paying 15 per cent less thanks to the collapse in the value of the pound. Never has low-hanging fruit dangled so tantalisingly close to a finance minister’s grasp.

Some talk of the agreeable and intelligent Derek Mackay as a future leader of the SNP, and he certainly has the chance to shine today. The Finance Secretary is reshaping the entire fiscal landscape of Scotland, and thanks to Brexit, getting the political space to do it.