Rachel Reeves made a major blunder this morning after being found out for not knowing how many children will be affected by her new tax rise on private school fees.

Yesterday, the Treasury quietly admitted for the first time that Labour’s plans to put VAT on school fees from January 2025 will force some children out of the sector and into state schools.

Campaigners against the plans have warned that such a large number of children may be forced out of private schools that it ends up costing the government money, as well as harming the education of those in the state sector.

However, this morning Ms Reeves failed six times to tell LBC listeners just how many children even attend private schools.

She was taken to task by Nick Ferrari, a pro interviewer for making sure politicians have done their homework, who asked her half a dozen times to spell out the key statistic, before giving in and telling the Chancellor.

He began: “What sort of number of children are you allowing for that might now be taken out of private schools?”

Ms Reeves replied: “Well the IFS have done an analysis of this and they say that a very small no. of children will move to the state system… I think it’s less than 10% of children

He repeated: “How many children are in private education?”, with Ms Reeves responding that 7% of pupils go to private schools.

Mr Ferrari pointed out he’d asked for a number, not the percentage, with Ms Reeves repeating the 7% figure for three more questions.

The LBC host eventually informed her that there are around 500,000 children in private education.

Ms Reeves derided the “obsession” with the 7%, rather than the 93% of children in state schools.

The 10% figure mentioned by the chancellor would mean around 54,000 pupils swarming into state schools.

The Education Not Taxation campaign has accused the IFS’s calculation of being inaccurate, however.

The IFS study from July last year says: “Our best judgement is that it would be reasonable to assume that an effective VAT rate of 15% would lead to a 3 – 7% reduction in private school attendance”.

The campaign group points out that the report also warns: “The effect of removing tax exemptions is likely to be different across different types of schools with different fee levels. However, predicting this with any level of certainty is near enough impossible”.

Education Not Taxation concludes: “Simply put, the IFS themselves have no confidence in their headline estimate of 3-7% of independent school students moving to taxpayer-funded schools”.

Treasury documents published yesterday said that the Government does recognise that Labour’s planned tax “may lead to increased costs for some parents and carers, and that some pupils may subsequently move into the state education sector”.