a pew research center poll, conducted between april and august 2017 and published in may 2018, showed that 59% of portuguese people supported same-sex marriage, 28% were opposed and 13% didn't know or refused to answer. when divided by religion, 82% of religiously unaffiliated people, 64% of non-practicing christians and 43% of church-attending christians supported same-sex marriage. opposition was 14% among 18-34-year-olds.