A great win for the Lib Dems - a stunning performance by UKIP. It was a double whammy David Cameron didn't want. Eastleigh is the sort of seat the Tories must win back if they are towin the next election with an overall majority.
They can't use the usual excuse of mid-term blues because their coalition partners won. Maybe voters who are unhappy with the government are more inclined to blame the Tories rather than the LibDems.
UKIP's success will increase the pressure on Mr Cameron from some of his backbenchers who are urging him To return to 'more traditional Tory values'. Nigel Farage thinks tonight's result will make a Tory leadership challenge more likely.
As the Tories bundled their candidate out of the hall through a media scrum - she refused to answer any questions from reporters - they must have been asking questions of their own: how can the result have gone so badly, and where do the Tories go from here?
Liberal Democrat leader Nick Clegg has hailed his party's success in the Eastleigh by-election.
Voters go to the polls today in the closely-contested Eastleigh by-election that is poised to heap pressure on the coalition Government.