The minister for children has admitted not knowing how much child benefit is worth in a faltering radio interview about Tory plans to make high earners eligible for more of the allowance.
David Johnston said “should have found out before I came on here” when he was asked for the figure during an appearance on LBC on Friday.
The minister had been on the show to promote the Conservatives' election offer to parents to raise the high-income child benefit tax charge threshold to £120,000.
Under existing rules, parents or parents' partners start to lose the allowance if they earn more than the £60,000 threshold, and it is taken away entirely when one's income tops £80,000.
Asked by presenter Nick Ferrari how much current child benefit is worth, Mr Johnston said: “That I'm afraid I don't know.”
“It's actually not a Department for Education policy, it's a DWP (Department for Work and Pensions) one.”
The broadcaster replied: “Sorry, is your title minister for children?”
“And you don't know what the child allowance is?”
Mr Johnston said: “Well we don't mind the benefits I'm afraid, but you're right, I should have found out before I came on here.”
“I'm sorry that I don't know the amount.”
As of April, child benefit is £25.60 a week for the eldest or only child in a family and £16.95 a week for younger children.
As part of efforts to switch the focus of the election campaign to taxation, the Conservative Party on Friday unveiled plans to allow people to keep some allowance on incomes up to £160,000.
Chancellor Jeremy Hunt said the proposals could amount to an average annual saving of £1,500 for 700,000 families.
The Tories said the move would “end the unfairness that means single-earner households can start paying the tax charge when a household with two working parents and a much higher total income can keep the child benefit in full”.
The party says the proposal will cost £1.3 billion in 2029/30 with the money set to come from a crackdown on tax avoidance and evasion.
It comes amid a wider fallout following Rishi Sunak's disputed claim that Sir Keir Starmer would hike taxes by more than £2,000.
The row stems from a document produced by the Conservatives which made a series of assumptions to estimate the cost that might be attached to potential Labor policies.
It said that Labour's plans had a £38.5 billion deficit over four years, the equivalent of £2,094 for every working household, which the Tories claim would be filled with tax hikes.
The UK statistics watchdog has criticized Mr Sunak's references to the figure, saying it is not clear enough that it refers to an estimate summed together over four years.
Labor has said the Tories are “lying” but the Prime Minister has since doubled down on the claim, telling ITV that the rival party is “obviously very rattled that we've exposed their plans to raise tax on people”.