Even the Eat Out To Help Out scheme failed to get the economy anywhere near the 4.6% rise analysts had been expecting.
It comes as restrictions are expected to be announced for pubs and restaurants in the north of England and the Midlands on Monday.
It also comes amid warnings of a deepening employment crisis as the Job Retention Scheme, that has supported the wages of almost 10 million people during the crisis, is wound down.
The Bank of England has predicted that the UK could have three million unemployed by the end of the year, while business groups say an exit from the EU without a trade deal in January risks deepening the damage.
British Chambers of Commerce head of economics Suren Thiru said: “The increase in activity in August largely reflects a temporary boost from the economy reopening and government stimulus, including the Eat Out to Help Out Scheme, rather than proof of a sustained ‘V’-shaped recovery.
“Although the UK remains on course to exit recession in the third quarter, the looming triple threat of surging unemployment, further restrictions and a disorderly end to the transition period means the recent rally in economic output is likely to be short-lived.”
Jeremy Thomson-Cook, chief economist at Equals Money said: “So much for the V-shaped recovery. The UK GDP data released this morning shows August’s rate of growth fell to a third of what it was able to reach in July, confirming that the UK’s recovery is not V-shaped.”