In response, the Prime Minister should hold his nerve. A pact with Ukip would risk further toxifying the Tory brand (53 per cent of the public have a negative view of the party) and, as his failure to block the appointment of Jean-Claude Juncker as head of the European Commission demonstrated, EU leaders do not give in to blackmail diplomacy. The biggest error that the Conservatives could make would be to mistake the noise for a signal and to shift Rightwards, alienating the centrist voters they need, not least in London, if they are ever to win a majority again.