Boris Johnson has been rebuked by the independent statistics watchdog over claims he made last month about universal credit.
The prime minister told MPs the welfare change, which rolls six benefits into one payment, had already succeeded in getting 200,000 people into work.
But the UK Statistics Authority said the number was only an estimate for when the change is fully rolled out.
The much-delayed system is now due to be fully rolled out in September 2024.
The watchdog had been asked to investigate the 200,000 jobs figure by Labour’s shadow work and pensions secretary Margaret Greenwood.
Mr Johnson had used it to defend government welfare changes during an exchange with Labour leader Jeremy Corbyn at Prime Minister’s Questions.
In a letter to the prime minister, the watchdog’s chairman Sir David Norgrove confirmed the figure was an estimate, rather than for “the effect so far”.
The jobs figure, estimated to be achieved by 2024/25, was made by the Department for Work and Pensions in its 2018 business case for universal credit.
It has already been questioned by the National Audit Office, which concluded the department would “never be able to measure” the impact on employment.
“It cannot isolate the effect of universal credit from other economic factors in increasing employment,” the NAO concluded in a 2018 review.
This is not the first time the chairman of the UK Statistics Authority has clashed with Mr Johnson over his use of statistics.
In 2017, Sir David criticised him for his claims during the EU referendum campaign that Brexit would save the UK £350m a week.
He added that the figure, used by Mr Johnson whilst he was foreign secretary, constituted a “clear misuse of official statistics”.