Portugal's centre-left ruling Socialists lost ground in an opinion poll published on Friday that left it with the narrowest lead in all recent surveys, keeping the ballot wide open just 10 days before a snap general election.
Prime Minister Antonio Costa's party dropped to 37% support, according to the survey by Catolica pollsters, from 39% in the same poll a week ago, while their main rivals, the centre-right Social Democrats, rose to 33% from 30%.
