By Jessica Frank-Keyes We’re three weeks into the election campaign and Labour leader Sir Keir Starmer is preparing to unveil his party’s manifesto for government. The document is Labour’s pitch to voters, and a series of promises as to what they would do with power – if granted it. After the Lib Dems, Conservatives and Green Party all also launched their manifestos this week, the nature of the campaign is now likely to shift. Politicians will be arguing about concrete pledges, as opposed to more loose interpretations of what their opponents might be suggesting. Here are three things to watch …