The PM faces a backlash after the Lib Dems win the by-election and the Tories finish behind UKIP in third place.
Counting in the by-election continues as the Lib Dems say they have held the seat and predict that UKIP has beaten the Tories.
Nigel Farage's party would crave UK political representation to match that of the Greens.
Rather than appealing for tactical votes from UKIP supporters in the Eastleigh by-election, the Tories should have supported a voting system that ends this dilemma.
Their manifesto might just look like a list of things that annoy people, but party members hold some views that should concern us, says Alex Andreou.
PM says that only "the parties that are going to form the government" should be included if the debates are repeated in 2015.
Ahead of the removal of restrictions on immigration from the two newest EU member states on 1 January 2014, UKIP puts the Tories under pressure.
The drift of some Tory MPs into a moralising absolutism is as big a threat as Ukip to the party's election chances.
If the party performs well in 2015 but fails to win a seat, our voting system will be questioned again.