The prime minister told MPs: “we have just cut taxes by £900 for a typical worker”.

He is talking about the impact of Chancellor Jeremy Hunt’s two cuts in National Insurance (NI) of 2p in the pound each, the second of which came into force earlier this month.

The average wage for a full-time employee is about £35,000, and that person will indeed pay about £900 less in NI this year as a result of the changes.

But that worker will also be paying tax on more of their salary because of previous government decisions. The independent Institute for Fiscal Studies estimates that they will actually only be £340 better off.