Boris Johnson will be forced to confront some difficult political choices as he assesses the Tory drubbing in Chesham and Amersham.
The Liberal Democrats claim the result has sent a “shockwave through British politics” by showing that seats in the “Blue Wall” of Tory seats in southern England are vulnerable.
The warning signs were there in the local elections in May – although Conservative eyes may instead have been tempted to look north, where further inroads were being made into previously safe Labour territory.
The party lost councillors in places including Tunbridge Wells, Surrey and Oxfordshire, as well as the West of England mayoralty.