The Morrison government needs to wake up. It spent the entire election campaign telling us the economy was strong despite clear evidence that was not the case, and now in the light of some of the worst economic growth figures this century it would have us believe all is going to plan.

If that is so, what the heck does that say about their plan?

At the Liberal party election campaign launch in May, Scott Morrison told the audience: “You know, it all begins with keeping our economy strong.”

It was a rather interesting use of the present tense “keeping”, as this week’s GDP figures have made abundantly clear the economy was not strong at the time of his speech, and has not been so for a year now (even worse, this was obvious even before Morrison gave his speech in May).

The 2018-19 financial year had the lowest growth since 2000-01, and it was the eighth worst year out of the 60 since 1960.

In the past 35 financial years only five have seen worse per-capita growth, and in the past 40 only four have seen lower productivity growth.

And yet we have the treasurer telling us that “the fundamentals of the Australian economy are strong”.

Good luck working out what they are, because if productivity is not a fundamental aspect of the economy then nothing is.

Perhaps those fundamentals are the government spending on the NDIS, aged care and flood relief? Because if you took those away, the economy would have shrunk in the June quarter.

At least the talk has shifted from keeping the economy strong; now the boast is all about the fact that it is not going backwards.

The prime minister told reporters on Thursday that “the Australian economy grew by 1.4 per cent, through the year at 1.9 per cent in year average terms, which was only slightly below what we said it would be in the budget for 2018-19”.

Only slightly below?

The April budget estimated growth would be 2.25%. In last year’s budget they were predicting growth of 3%, by December in the mid-year fiscal and economic outlook that had been downgraded to 2.75%

So it went from 3% to 2.75% to 2.25% before finally hitting the reality of 1.9%.

Households have seen living standards fall for the past three-and-a-half years, and they are now back at 2010 levels.

Not exactly a sign of things going to plan.

And the plan is the big issue, because right now the government is trying very hard to do two things – convince you they have a plan, and that what they had planned previously has worked.

In effect they want you to both forget and remember that they have been in power for the past six years.

They want to respond to these awful economic figures (the first time since 1991 that we have seen four consecutive quarters of trend growth below 0.5%) as though they have been elected to fix the problem, while also saying that the plan they had put in place before the election doesn’t need any tinkering.

Morrison suggested on Thursday that they have “a plan we put in the budget. The tough economic circumstances we face are no surprise to the Coalition. That’s why we framed the budget we did.”

We’ll leave aside the fact that the 1.9% growth did actually surprise them because it took just the months of May and June for the figures in the April budget to be overly optimistic.

But if they saw this coming, why then, despite boasting as the treasurer did this week of “the commonwealth’s 10 year $100 billion pipeline of infrastructure spending”, did public investment fall in the June quarter and see its lowest annual growth for nearly four years?

Was that the plan?

A year ago the expectation was that interest rates would likely start rising. Now the expectation is that the economy is so weak that despite already having had two interest rate cuts since then, at least another two will happen in the next eight months.

Now, sure, you can say Donald Trump and his trade war idiocy is partly to blame. But our exports remain strong – although we are unlikely to see such good growth in the future, should iron ore and coal prices continue to weaken.

The real fault for this economy is domestic. Households have seen their living standards fall for the past three-and-a-half years, and they are now back at 2010 levels.

That is why household consumption growth is the worst it has been for a decade – with nearly half of the growth in spending on rents and housing costs, and health items. The growth in spending on recreation and culture, furnishings, eating out and staying in hotels is all below what you would expect it to be; essentially, we are shifting our spending towards necessities.

And through it all the government remains committed to a surplus because ... well, because that was the plan – the same plan that originally had the economy growing at 3% rather than the current 1.9%, the same plan that had the unemployment rate staying at 5% rather than rising as it has this year to 5.3%.

If that was the plan, it failed. And it is time for the government to acknowledge it needs a new one.

• Greg Jericho writes on economics for Guardian Australia