In a year of seismic political events the Liberal Democrats’ by-election success last week in Richmond Park only registered as a minor tremor, but its implications for electoral politics in Britain may prove to be long lasting.

On the one hand, the 21.7 per cent swing to the Liberal Democrats was a welcome fillip for a party which 18 months ago had diced with electoral oblivion.

Sarah Olney’s victory illustrated that the Liberal Democrats had returned to its pre-coalition status as a party of protest with a ruthless capacity to squeeze votes from other parties and build tactical alliances. The party also flexed its muscle on the ground, with hundreds of workers descending on the constituency to socialise and then mobilise the Lib Dem vote.