On the face of it, the 12% jump in retail spending last month fits with the notion that the economy will bounce back quickly from Covid-19 once the lockdown restrictions are fully lifted.

May’s rise occurred even before non-essential stores were allowed to start trading in some parts of the UK on 15 June, so the increase appears consistent with the idea of a V-shaped recovery: an initial fall as the country went into lockdown in late March; an 18% drop in April when the quarantining was at its most intense; then a much stronger pick-up than expected in May.

There are, though, reasons to be just a little bit cautious. For a start, retail sales volumes in the three months to May – a better guide to the trend – were still a whopping 14% lower than in the three months to February, the last period in which spending was not pandemic affected.

Nor should retail sales be confused with consumer spending. Retail sales are the goods that people buy, either in the shops or online. Consumer spending includes services such as eating out in restaurants or staying in hotels – and those bits of the economy remain shuttered.

Retail sales account for only about a third of overall consumer spending and there is, as Samuel Tombs of Pantheon Consulting notes, every possibility that some of the money that would have been spent on services was instead spent on retail goods. He gives the example of people using the money saved from gym memberships to buy fitness equipment instead.

The strains on the economy were underlined by separate official figures for public borrowing, which was a record £55bn in May as a result of the double-edged impact of the lockdown. The government is being deprived of tax revenue at the same time as it is paying up to 80% of the wages of those furloughed.

By borrowing more than £100bn in the first two months of the 2020-21 financial year, the UK is adding quickly to its national debt – the sum of all the deficits, and the somewhat rarer budget surpluses, over time. As a share of the economy, the national debt has climbed above 100% for the first time since early 1963, the year of the Profumo scandal and Beatlemania.

Back then, of course, the debt ratio was coming down from the much higher levels caused by the borrowing during the second world war. Record levels of peacetime borrowing and a rising debt ratio make the treasury uncomfortable, which is why the furlough scheme is being tapered from the start of August and will be wound up in October.

The big unknown is whether households are going to carry on spending as the wage subsidies are removed and unemployment continues to rise. If they do, the chances of a V-shaped recession will be greatly improved – but it is premature to say that they will.