It’s no longer a question of “if”, but of “when” and “how”. The pressure for a market-wide price cap on standard variable tariffs (SVTs) has reached boiling point. John Penrose is a senior Conservative MP: for him to be leading a campaign for such a cap, with the support of one-third of his fellow MPs right across the House, puts the government in an almost impossible position – particularly as the price cap he is campaigning for was promised in the Conservatives’ own manifesto.