The Staggers 18 June 2021 Why the Conservatives’ defeat in the Chesham and Amersham by-election is a shocking blow The Liberal Democrats' extraordinary victory in a previously safe seat shows the perils of the Tories' electoral strategy. Ed Davey, leader of the Liberal Democrats, and Sarah Green, winning candidate of the Chesham and Amersham by-election Sign UpGet the New Statesman's Morning Call email. Sign-up The Liberal Democrats have secured an extraordinary victory in the Buckinghamshire constituency of Chesham and Amersham, overturning a majority of more than 16,000 to take this previously safe seat from the Conservatives. Sarah Green, the Liberal Democrat candidate, won with a majority of 8,028 and 56.7 per cent of the vote share. She secured 21,517 votes, compared with 13,489 for Peter Fleet, the Conservative candidate. It is a major victory for the Liberal Democrat leader, Ed Davey, who said following the result that "across the south, the Tory Blue Wall is beginning to crumble.” [Hear more on the New Statesman podcast] To anyone who visited the constituency in the days before the by-election, it was clear that the narrative around a “Blue Wall” of previously strong, but crumbling, Conservative support in the south was more than just Liberal Democrat spin. This was the gradual re-alignment of post-Brexit in action, as voters who had never voted for anyone but the Conservatives on doorstep after doorstep expressed their intention to vote Liberal Democrat for the first time. The two dominant issues in the campaign were HS2, which cuts through the constituency, and planning reforms, which could see the Conservative government impose high targets for new home building on local areas, with Buckinghamshire one of the counties the most affected. The Liberal Democrats made hay of both issues, but on doorsteps, voters testified to a larger feeling of drift from their traditional party, many saying that it had begun with Brexit. This is compounded by demographic changes in the constituency that mean that the seat was slowly trending younger, more cosmopolitan, and Liberal Democrat, anyway, as a function of the constituency having two commuter towns, accessible from London by tube. (You can read my long report from Chesham and Amersham for more of that mood.) But whether this high-profile by-election win is an acceleration of changes that were maybe gradually coming anyway, this remains an extraordinary upset for the Conservatives, who would have been facing some soul-searching and worry even if they had held onto the seat on a slim majority. But with a majority this sizeable, particularly when the Conservatives are performing well nationally, this is a huge blow for southern Conservatives who were already deeply worried about the party’s electoral strategy. “Even the Tory villages on the outskirts voted Lib Dem,” one source on the Lib Dem campaign says, delightedly. “We thought the towns would go us, but these villages were unthinkable to us.” A defeat of this size will amplify and accelerate the conversations that have already been happening with the Conservative party. This defeat will be seen as proof that the party’s strategy of targeting northern Labour heartlands has left their southern base wide open, with no convincing electoral offer for seats that have been solidly blue for decades. Certainly Boris Johnson’s promise of focusing on “the people’s priorities” didn’t speak to voters here when he visited the campaign. In the short term, southern Tories will push for changes to the planning laws that were a factor in this election defeat, and the leadership will be forced to make further concessions to voters in shires constituencies. But the bigger post-Brexit realignment is something this Conservative party has actively sought, and it will be harder to fix, even if they want to. For all that this strategy delivers shocking Conservative gains in places like Hartlepool, the deep cultural realignment of politics post-Brexit is causing shocking Conservative losses in its own heartlands. › Why has Edwin Poots resigned as DUP leader after 20 days? Ailbhe Rea is political correspondent at the New Statesman. She co-hosts the New Statesman podcast, discussing the latest in UK politics. Subscribe For more great writing from our award-winning journalists subscribe for just £1 per month!