As Sajid Javid prepares to deliver his spending round statement this week, Britain is yet again on the brink of another week of Brexit chaos. But in his debut Commons set piece, the chancellor will be looking to make another point to distract from the turmoil to mark a potentially pivotal turning point: the end of austerity.

Thanks to the hard work of people in Britain, he will undoubtedly say, the decade of fiscal restraint has now run its course. This is a big moment for the country: public services will get the money they badly need, and Britain will live within its means.

There have been turning points in the public finances throughout history, when the spending taps are turned off and services are squeezed, before an eventual backlash as services come under strain, forcing the taps back on again.

From the Geddes Axe cuts of the Conservative–Liberal coalition of the 1920s to fix the public finances after the first world war, and a similar act by the wartime coalition of the 1940s, there have been more than a dozen periods of belt-tightening in the past century.

Since the spending squeeze imposed by the Conservative–Lib Dem coalition in the early 2010s, Britain has been subjected to one of the longest periods of restraint on record. More than half of current MPs have no parliamentary experience from before the banking crash, entering parliament since 2010 and knowing only the austerity age, as have millions of young voters who have turned 18 since.

But for the first time since the imposition of austerity in 2010, Javid’s spending round is expected to mark the return of real-terms gains for overall departmental spending. That has not happened since 2007 – back when the chancellor was still selling risky bonds in the boom years of his investment banking career.

But there is one big problem with declaring this return to normal: the political and economic situation is anything but. Britain is on the cusp of recession and a no-deal Brexit is likely to make matters worse.

For that reason the spending review is only covering a 12-month period. The big decisions will need to come afterwards, given the huge scale of the uncertainty for the public finances should Britain crash out without a deal.

The turning point this week is therefore more about the formalisation of a series of ad-hoc policy announcements gearing the country up for a showdown, rather than the proper end of austerity required.

There are two issues it will confront. Javid says the spending round is about clearing the decks to allow greater focus on Brexit, but it will do anything but. Attempting to schedule time in the Commons this week is about running down the clock, robbing MPs of time to debate the impact of Boris Johnson extracting Britain from the EU do or die.

It is also about paving the way for a possible general election. Leading voters to the polling stations is invariably accompanied by tax cuts or spending increases. Johnson will hope that splashing the cash sends a message: trust me. I can carry off Brexit and raise your living standards all at the same time.

The Tories have shaken the magic money tree with abandon, producing crowd-pleasing dollops of cash for public services since Johnson’s elevation to No 10 in July.

Taken together, the government’s announcements so far total about £6bn of extra spending and borrowing in 2020-21, with the largest chunk going towards reversing cuts to per-pupil funding in schools. The government will also reveal the cost of hiring 20,000 more police officers, and about £1.8bn has been announced for hospitals.

But it is a high-risk strategy when a no-deal Brexit could sink the country into recession and damage the public finances, making it tough to bring about the end of austerity.

The chancellor said last week that there would be no “blank cheque” for departments and that he would stay within the fiscal rules set by his predecessor, Philip Hammond.

Javid is bound by the rules to keep public debt falling as a percentage of GDP and to ensure borrowing, adjusted for the state of the economy, is below 2% of GDP in 2020-21. The self-imposed rules also call for the government to bring the public finances into balance by the mid-2020s – a promise economists say will be almost impossible to keep.

The chancellor probably has headroom of about £14bn to stay within the rules next year on the forecasts for the economy he is using, based on the assessment made by the Office for Budget Responsibility in March.

But the promises shouldn’t be worth much, as the economy has changed significantly since then. Javid is escaping proper scrutiny by using these forecasts to talk about ending austerity while keeping the country’s finances on an even keel.

The Resolution Foundation estimates that a true reflection of the finances to account for Britain skirting recession in recent months cuts his headroom by £10bn. According to Yael Selfin, the chief economist of KPMG, a no-deal Brexit could damage the public purse to the tune of about £40bn.

“It would not make sense to rush any additional spending at this stage,” she said. “It makes sense to be prudent and say: ‘I’m going to hold back to leave a bit of margin for Brexit.’”

Either way, the public finances will look very different by the end of the year, making this week’s spending review a short-term project: the promise to remain in keeping with the fiscal rules will be broken in months, if not weeks.

All of this brings back ironic memories of the long-term economic plan, the ubiquitous soundbite of David Cameron and George Osborne. It had been the key plank of the 2015 election campaign, helping the Conservatives to win an unexpected majority against Ed Miliband.

That too was electioneering rhetoric, but at least considered management of the economy over a longer period of time than Javid is working towards.

Britain badly needs a long-term economic plan. But there is no such strategy as Javid and Johnson look to get through the next few weeks.

The UK has significant scope to raise spending on public services, given historically low borrowing costs on the international market. The deficit has been cut down to a 17-year low. Rather than a panic-driven spending round, real issues must be tackled over the long term, such as reducing child poverty, improving social care, fixing the country’s productivity puzzle and reversing cuts to local council services.

A turning point might have arrived. But Javid could be leading us dangerously in the wrong direction.