Pious hope of the week: the estimable Paul Johnson, director of the Institute for Fiscal Studies, says in The Times today that it would be “preferable for the electorate to know what is planned for them than increases to be sprung on them after they have voted”. Quite so: yet as the IFS noted in its Green Budget last month, history suggests that general elections tend to be followed by unannounced tax rises. “Every election since 1992” says Mr Johnson “has seen the chancellor announce large tax increases within a year of polling day, none of which were spelt out to the electorate beforehand”. Anyone who has looked at the numbers knows that despite five years of so-called “austerity” there is a big hole in the public finances which still needs to be – and will be – filled by painful measures after polling day. We have been warned.