Chesham and Amersham by-election: Ed Davey with Lib Dem supporters

Sir Ed Davey has celebrated his party's win in the Chesham and Amersham by-election by breaking down a model blue wall.

The Lib Dems overturned a big Tory majority to win the Buckinghamshire seat.

Politicians and pundits have been talking of a Conservative blue wall, and a Labour red wall, in the parties' former heartlands which could become vulnerable to other parties.