The ruling Conservative-Liberal Democrat coalition has long faced criticism for its policies and U-turns, from health care to education to foreign policy. Voters' distrust of the faltering European Union helps partly explain the rise of Ukip. The party wants Britain to leave the EU. Farage, a member of the European Parliament, is a famous Euro-sceptic.
Yet Ukip itself has been mired in scandals. Its policy manifesto is deemed by critics as a messy mash-up of ideas. The party may have little staying power.