Postpublished at 12:15 Greenwich Mean Time 13 March
Starmer says the Labour party will not be sticking to the Conservatives' unfunded promise.
He says 80% of the National Insurance is spent on social security and pensions, and 20% on the NHS, so Sunak is either cutting pensions or cutting the NHS, or raising other taxes or borrowing money.
"Which is it, prime minister?" he asks.