A pledge to abolish inheritance tax would be an irresponsible measure

The ‘death tax’ is unpopular until people are asked: what tax rises or public spending cuts would you prefer instead?

If the Conservatives promise to abolish inheritance tax, they will be asked: ‘How will you pay for it?’ (Getty)

Inheritance tax is the Conservatives’ “smash glass in case of emergency” button. That the prime minister is thinking about a promise to abolish inheritance tax for his election manifesto is a measure of his desperation.

The device was last activated by George Osborne, when he was shadow chancellor, and he and David Cameron were terrified that Gordon Brown might call an election in the autumn of 2007. Mr Osborne’s plan to exempt the first £1m from tax helped unite the Tory annual conference and secured headlines that helped turn the opinion-poll tide in the party’s favour.