The issue focused by experts at the Conservative Party conference has come down to whether voters believe David Cameron has gone far enough in tackling immigration.David Cameron says his proposals will limit illegal immigration by banning EU migrants from claiming benefits for four years and introducing tougher checks for overseas workers.His proposals were criticised by Ukip leader Nigel Farage who accused Mr Cameron of putting himself above the interests of Britain's workers.Speaking at the Conservative conference in Birmingham, Mr Cameron said his proposals would prevent illegal migrants entering the UK from claiming benefits from October