Within 20 minutes of Rishi Sunak announcing plans for a July election, Keir Starmer was up delivering his response. The Labour leader’s first pitch of the campaign could be summed up in six words: stop the chaos, vote for change. It is a neat encapsulation of Starmer’s four-year-mission as Leader of the Opposition – making his party electable again by fashioning it as the safe, reliable, respectable mainstream of British politics.