Retail sales rebounded in May after an unprecedented fall in April as DIY stores and garden centres reopened and supermarkets continued to perform strongly, according to official figures.

UK sales rose by 12% last month as the easing of the lockdown spurred demand for paint, garden equipment, electrical goods and homewares, increasing the amount bought in non-food stores by 24%.

A rush back to DIY shops, where sales jumped by 42%, gave the biggest push to overall sales, according to the figures from the Office for National Statistics.

It followed an 18.1% fall in retail sales during the first full month of lockdown in April, which was the biggest drop on record.

Despite the bounceback in May, high street sales were not back to pre-lockdown levels.

“Sales were still down by 13.1% on February before the impact of the Covid-19 pandemic,” the ONS said.

In a clear message that shoppers have changed their habits during the lockdown, the biggest gains went to online shops, which accounted for 33.4% of all spending in May, compared with the 30.8% reported in April and an average of 18% seen last year.

Last month, the British Retail Consortium, which represents high street stores, warned the lockdown had cost non-food shops £1.8bn in lost sales each week and many retailers would not bounce back.

Neil Birrell, the chief investment officer at the asset manager Premier Miton, said the sales figures showed the UK was following the rest of Europe out of the lockdown period. “Retail sales for May surprised on the upside, showing a much bigger recovery than expected, month on month.

“This data does not include the effect of reopening the high street this week and it gives the optimists renewed hope that the recovery in the UK will come through as it has in other countries as lockdown eases.”

However, Samuel Tombs, the chief UK economist at the consultancy Pantheon Macroeconomics, said the picture remained grim for most retailers as many households hoarded cash.

“Unofficial indicators of households’ overall spending remain very weak; Barclaycard, for instance, reported that spending fell 26.7% year over year in May, not vastly better than April’s 36.5% decline,” he said.

Jeremy Thomson-Cook, the chief economist at the money management firm Equals, warned the bounceback in sales could evaporate if the government failed to maintain the momentum of last month from shops reopening.

“We can see that consumption has risen on three factors: access to more retailers, the need to treat oneself and likely boredom. How long these drivers can remain positive depends much more broadly on the jobs market moving forward with cliff edges seen as the furlough scheme winds down and some consumers face claiming universal credit instead of their government-supported wage.”

Petrol sales also played a part in the recovery after the biggest fall in consumption on record in April.

Petrol usually makes up about 10% of retail sales but that has fallen back to nearer 5% in the pandemic as people use their cars less.

The ONS said the last two months revealed wild swings in the levels of consumption, with a large recovery after travel restrictions began to ease in May. It said fuel sales increased by 49.1% when compared with April but this was still down 42.5% when compared with February, before government travel restrictions were in place.