Rival in PM race calls on frontrunner Johnson to answer 'difficult questions'

The frontrunner to be Britain's next prime minister, Boris Johnson, came under renewed pressure on Sunday to explain the circumstances of a late-night row between him and girlfriend that led to the police being called to their home.Polls conducted for the Mail on Sunday newspaper before and after Britain's front pages were dominated by the argument showed that Johnson's lead over rival Jeremy Hunt, the foreign minister, had evaporated amongst all voters and had narrowed among supporters of his r