Over the past few months the rumours about the next general election have ebbed and flowed. But finally, at 5pm on Wednesday, Rishi Sunak stood at a lectern in front of 10 Downing Street and named the date – the election will be held on 4 July. Despite the fevered speculation, it caught many by surprise – most political experts were expecting an autumn date. And the announcement itself was far from the slickest. Sunak had to battle against not just a downpour but also a sound system blaring out the Labour election campaign classic Things Can Only Get Better. So what political calculations had the Conservatives made in choosing the July date? Guardian columnist Jonathan Freedland tells Helen Pidd how everything from an economic upturn to private school holidays may have played a part, and discusses whether or not anything can now obstruct Labour’s path to victory.