The legalisation of same-sex marriage in the state of Rhode Island prompted condemnation from the Archbishop of San Francisco, who called the law an injustice to children.

On 2 May Rhode Island became the tenth US state to allow equal marriage when its Governor signed the bill into law, after it passed a second vote in the House by a very wide margin.

The Archbishop of San Francisco, Salvatore Cordileone, responded by calling the legislation a “serious injustice”, and arguing that it would harm vulnerable children.

“Marriage is the only institution that unites a man and a woman to each other and to any child conceived of their union,” Cordileone said. “While those making great sacrifices to raise their children in less than ideal circumstances need and deserve our love and support, we cannot claim to have a just society if we do not look out for the most vulnerable among us: children.

“That means preserving in the law the principle that every child deserves a mother and father united in marriage. That means supporting in our institutions and in our culture the true and unique meaning of marriage.”

This was not the first inflammatory remark made by the Archbishop on marriage equality.

In January, he said legalising same-sex marriage would be like legalising “male breastfeeding”.

The leader of Rhode Island’s Roman Catholic Diocese, Bishop Thomas Tobin, also criticised the change in law, saying it “profoundly disappointed” him.

He added that Catholics should not attend same-sex weddings, as “to do so might harm their relationship with God and cause significant scandal to others”.