Jeremy Corbyn wanted the media to talk more about his party’s policies and less about his leadership, and he has got his wish. The Labour leader’s idea to fund free school meals for every primary school pupil, funded by imposing VAT on private school fees, was all over the news bulletins on Thursday morning. Offering free stuff to children is a pledge in the classic electioneering style, and shows that if Theresa May were thinking about going to the polls earlier than 2020, Labour are already in manifesto-building mode.

The policy itself has its problems. I don’t doubt that there will be plenty of voters with primary school-age children who will be attracted by the idea of free school meals (they are already funded up to the age of seven, so this is a free lunch ticket, doubled). There will also be many voters who cannot afford to fund private education and wish their own child’s school had the vast playing fields and shiny swimming pools they walk past every day. But increasing fees by 20 per cent would push those parents already breaking the bank to go private into the state sector, putting more pressure on already over-subscribed, cash-strapped schools, and cancelling out any financial advantage. Smaller independent institutions would risk closure, also increasing the burden on state schools. The private sector would become even more elitist, remote islands of privilege where only the children of the mega-rich could afford to go.

When it comes to extending free school meals, universalism in public services is an important principle - the one in which services only for the poor become poor services - when applied to the NHS or education, but funding school meals for all does not fit that principle. School dinners have to meet nutritional standards, whether they are free or not. It isn’t right that a policy that takes money from one group of middle class parents simply goes to help another.

There is more that private schools can do to justify their charitable status. Many schools open their luxurious facilities to the state sector, but on a tokenistic basis. Yet far more damaging to the prospects of disadvantaged children is not wealthy parents paying for a private education but the Government’s drive for new grammar schools, which will entrench divisions of class and wealth. The grammar schools policy poses a generational threat to social mobility, so why aren’t Corbyn and Angela Rayner, the shadow education secretary, making more of a fuss about it, particularly when it is something that affects all children?