A £2,000 cap on salary sacrifice would cost a Renault 5 driver £606 a year and raise HMRC up to £1 billion

Britain's electric company cars cost the Treasury £1.4 billion a year, and nobody publishes the bill. The cap is the one the Chancellor already set for pensions. An Audi driver on £110,000 would pay £3,190.

In the 2019/20 tax year about 5,000 people in Britain had a fully electric company car. Five years later it was 465,000.

Over the same five years the number of company car drivers rose by 120,000, and the tax they paid fell by £1 billion.

This is the second piece in a pre-Budget sequence on who is about to pay for taking levies off energy bills. The first was about the heat pump grant, a cut that would fall on wealth. This one falls on income. The last piece adds up the bill.

It is also the larger of the two, and nobody is talking about it.