The Conservative Party’s promise to provide free breakfasts to all primary school pupils will cost three times as much as the £60m they originally suggested.

In their manifesto for the 2017 General Election, the Tories said they would drop universal infant free school lunches and instead introduce free breakfast for pupils.

In a statement published the night before the manifesto release, the party argued dropping free lunches would save £650m and the new ‘breakfast clubs’ would cost £60m.

However, research by Education Datalab suggests the real cost of providing breakfast to the 3.7 million children enrolled in state primary schools will be closer to £174m per year.

The £60m figure — which the Conservatives are distancing themselves from — is thought to have come from an Education Endowment Foundation’s evaluation of a scheme called Magic Breakfast, which provides free breakfasts in schools serving deprived areas.

According to this evaluation, writes Education Datalab’s Philip Nye, the total annual figure of non-staffing costs will come to £43.4m (£11.86 per pupil per year). Add to this an estimated £20m in staffing costs and you get £63m.

However, the evaluation is based on an average across all pupils enrolled in the schools that took part in the study rather than on actual pupil take up, which was only 23.6%.

Mr Nye argues that while take up of the breakfast offer on a national scale will not be 100%, for many it may be seen as a a substitute for morning childcare. ‘This would suggest,’ he said, ‘that take-up might actually be highest in areas where parents already currently pay for morning childcare.’

The Magic Breakfast staffing costs also ‘seem low’, Mr Nye said. If they were scaled up to a national level, they would translate to each school spending just £6.26 per day on staffing.

Mr Nye estimates a more accurate figure might be £174m. This is based on the assumptions that the cost per pupil of food is 25p; a staff-pupil ratio of 15:1 is used; the breakfasts are delivered by teaching assistants or support staff, who have to be employed for an extra hour each day; and take-up is 20%.

A Conservative spokesman said: 'We will ensure that all primary schools can offer a free school breakfast to every child in every year of primary school as we set out in our manifesto – independent evidence shows this is a cost-effective way to improve education and health results for pupils.

'More broadly, we will increase the schools budget so that by 2021/22 we will be spending £4bn more on schools than now. This represents a real terms increase for every year of the Parliament, underpinned by a strong economy.'