Today I’ll set out my pledge to parents, to keep politics out of the classroom. Parents should not have to worry about political activism seeping into lessons; it erodes standards and pollutes minds. Under us it wouldn’t happen.

In 1967 Britain had more electric vehicles on its roads than every other country on earth put together, and they were all delivering milk. There were tens of thousands of them. The milk float: open sided, battery under the floor, top speed of about 15 miles an hour, and a whine you could pick out in your sleep. It was charged overnight at the depot and was back there by lunchtime. It carried glass bottles. Each one was collected from your step the next morning, washed and refilled. A bottle went round like that 20 or 30 times before it broke. The foil cap went for scrap. There was no other packaging. The milk had come from farms within a few miles, through a local dairy, and was on the step before 7. So here is what the country had. A zero-emission delivery fleet. Reusable containers with a return rate any modern scheme would kill for. No plastic. A supply chain you could cycle the length of. A man who noticed if an old lady's bottles were piling up, and knocked. It was dismantled in about 15 years, because a supermarket could sell milk a few pence cheaper in a plastic jug as a way of getting you through the door. Every piece of that system is now the subject of a government target for 2040. It was running in 1967, silently, in the dark, and nobody thought it was worth a mention.