A Republican candidate for the House in Washington state has compared same-sex marriage with polygamy.

When asked his position on same-sex marriage on Thursday at a candidate forum, Republican Pedro Celis brought up polygamy.

He said: “Marriage is something more for religion to decide… Is this marriage or not? Polygamy—is it fine or not? It’s a religion thing.”

The former Microsoft engineer was backed by the National Republican Congressional Committee, to run against Democratic Representative Susan DelBene for the first Congressional district of Washington.

According to reports, Celis is considered by the committee to be on a “clear path to victory”.

Celis in 2012 voted against Washington’s initiative to legalise same-sex marriage.