Rishi Sunak has been slammed by the UK statistics watchdog for wrongly claiming that government debt is falling.

The prime minister made that one of his five pledges to voters at the start of the year.

He claimed in a social media video, and also in the House of Commons, that debt was falling.

But Sir Robert Chote, chair of the UK Statistics Authority, said that was misleading.

In a letter to Lib Dem Treasury spokesperson Sarah Olney, he said Sunak’s office said the claims referred to the Office for Budget Responsibility’s forecast that net debt would be falling as a proportion of GDP in the final year of its five year forecast.

Sir Robert said: “The average person in the street would… likely have assumed that he was claiming that debt was already falling or that the government’s policy decisions had lowered it at the fiscal events – neither of which is the case.’

He added: “This has clearly been a source of confusion and may have undermined trust in the government’s use of statistics and quantitative analysis in this area.”

Sarah Olney said: “Rishi Sunak knows he has no good story to tell on the UK economy so he has resorted to making one up.

“The least this no-growth Prime Minister could do is be honest about it with the British public.

“Instead, he has reached for the Boris Johnson playbook and is undermining trust in politics. This is desperate stuff from a desperate prime minister and it is right that he has been called out on it.

“Rather than using smoke and mirrors to cover up his own failings, Rishi Sunak needs to come forward with a real strategy to rebuild the economy after the Conservative Party crashed it.”