Whatever its result, the next election will bring a wave of change to the House of Commons. So far, 90 of 650 sitting MPs have announced they will not be seeking re-election. Of those, 14 are former secretaries of state – 11 of them Tory – and nine are select committee chairs. This is the highest number of departing MPs since 2010, with more retirements expected to come. The exodus is greater on the Tory benches, which are on track for their biggest wave of departures since the 1997 Labour landslide. High-profile former cabinet ministers including Sajid Javid, Ben Wallace and Dominic Raab – all of whom in other circumstances might have risen further in their political careers – are among those stepping down. The 11 Conservative former secretaries of state who are leaving have nearly 40 years of cabinet experience between them. Now senior Tory figures are worried these departures will mean that, win or lose, the party will be left with a particularly inexperienced crop of MPs at the next election. One Tory source said: “There’s this question of how much experience the new intake will have … We’re grappling with two huge foreign affairs crises. Where are the foreign affairs experts?” Nick Gibb, who has served three stints as schools minister adding up to more than a decade, and Tracey Crouch, the highly regarded sports minister between 2015 and 2018, are also standing down. As important as any minister to preserving Conservative party institutional knowledge is Graham Brady, the chair of the 1922 Committee of backbenchers. Brady has overseen three Tory leadership contests in the past five years but is among those who have announced he will not be seeking re-election. On the Labour side, a trio of grandees are leaving parliament – Harriet Harman, Margaret Beckett and Margaret Hodge, who are in their 70s and 80s. The long-serving former Labour chief whip Nick Brown, who announced his resignation from the party over a long-running investigation into a complaint against him, is also retiring. The fact that Tory MPs make up the majority of those leaving is unsurprising – there are more of them than MPs of any other party. But another main factor is Labour’s commanding lead in the polls, which has convinced many Tories to start thinking about life after politics. “We have been in power 14 years,” a Conservative MP who is retiring said. “A lot of people who are going have been ministers or secretaries of state. It’s likely we will go into opposition. A lot of them have done opposition – and you don’t like being in opposition.” Even MPs who have only been in parliament for less than a decade have had to contest a series of big votes in close succession – the election in 2015 was followed by the 2016 Brexit referendum, the 2017 election and the 2019 election. Philip Nye, who has been tracking the data for the Institute for Government, said: “There are quite a lot of big names this time: we’ve got Dominic Raab, Sajid Javid, Matt Hancock. It will be a lot of experience leaving parliament whoever wins the next election.” “A lot of those standing down now entered parliament in 2010 so have been here for 14 years. If you’ve been in office for a long time, people are looking to step away from public life and personal circumstances have changed. “Saying that, there will also be the factor of people weighing up their options – either because of the way the polls are looking, or because of boundary changes and the effect that that’s having.” The boundary changes mean several MPs find themselves with constituencies that have been altered beyond recognition. A few Tory MPs who have said they are not standing again are actually hunting for new seats to apply for. Jonathan Djanogly, the MP for Huntingdon, decided to step down after failing to get selected to stand in a newly redrawn constituency covering his area. Others have cited the growing challenges of being an MP, including threats and abuse. The justice minister, Mike Freer, announced he would not seek re-election after a string of incidents and threats, including a near-encounter with the man who went on to murder the former Southend West MP Sir David Amess. “Being an MP is just exhausting,” the retiring Conservative MP said. “Your time is not your own. Your family give up so much.”