The first Westminster byelection since the resignation of Boris Johnson and Liz Truss and the financial fallout from the mini-budget takes place on Thursday. Polls will close at 10pm in the City of Chester constituency in the first electoral test for Rishi Sunak. The byelection was triggered by Labour MP Chris Matheson resigning in October after allegations of sexual misconduct. Parliament’s bullying and harassment watchdog and the standards commissioner found he had violated the Commons’ sexual misconduct policy. The byelection comes after a year of turmoil for the Conservatives, including byelection losses in Wakefield and Tiverton and Honiton in June and the Partygate scandal, which contributed to Johnson’s resignation in July. His successor, Truss, resigned after only 45 days in office. Labour, which has a majority of 6,164 votes in the affluent constituency, is expected to retain the seat. However, its history is more mixed. In 2015, Labour won by just 93 votes, making the City of Chester seat the most marginal in the country. In 2010, the Conservatives took the seat from Labour with a 2,583 majority. Labour could also be concerned because the last time a byelection was held due to one of their MPs standing down in disrepute they lost what was seen as a safe seat. Mike Hill resigned from his seat in Hartlepool in 2021 after allegations of sexual harassment and Labour went on to face an embarrassing defeat in the resulting byelection, losing the seat for the first time in its history. Local councillor Samantha Dixon is Labour’s candidate in Thursday’s byelection. In the past month, senior party figures including Angela Rayner, Ed Miliband and Richard Burgon have visited to campaign. The Conservative candidate is Elizabeth Wardlaw, a nurse who is also a local councillor. A result is expected at around 3am on Friday.