How worried should Labour be? The electoral risks are mounting. Labour has lost half of its 2017 support, and some polls now put them behind the Lib Dems overall. Jeremy Corbyn's personal ratings have slumped since the 2017 election and are now the worst ever recorded for an opposition leader. Labour optimists will point to the party's dramatic turnaround in the previous general election campaign as evidence that there is no need to panic. Once an election is upon us, Remain voters will again recognise that Labour is the only viable alternative to a hard Brexit Conservative government, and will return to the fold. The Lib Dems' rise may even play out in Labour's favour, if the Lib Dems challenge the Conservatives in southern English seats where Labour is out of contention, while being tactically squeezed in Conservative-Labour marginals where Labour is best placed to defeat the Conservatives.

Robert Ford is professor of Political Science at the University of Manchester and co-editor of Sex, Lies and Politics