The leaders of the major political parties have been travelling across the country on the campaign trail since the 2024 General Election was called. As there is limited time to visit all constituencies, the leaders of the three main parties – the Conservatives, Labour and the Liberal Democrats – have been visiting battleground seats ranging from ultra-marginal to constituencies with huge Conservative majorities. On Monday, Sir Keir Starmer visited Kettering and Northampton South, which would both need hefty swings in the share of the vote for Labour to gain them from the Conservatives. Ketteri…