Italians are voting in a referendum which is being closely watched for further signs of anti-establishment sentiment in Europe. <br/><br/>The vote, called by centre-left Prime Minister Matteo Renzi, is on plans to streamline Parliament but is expected to be used by many as a chance to register discontent. <br/><br/>Populist parties have campaigned for a "no" vote and Mr Renzi has said he will resign if he loses. Opinion polls suggest he faces defeat.