Alliance party leader Naomi Long has hit out at the First Minister Arlene Foster as "childish and disingenuous" for saying online abuse make her even less likely to support gay marriage.
rs Foster made the comments while defending the DUP's continued blocking of gay marriage by using the petition of concern at Stormont.
She told the BBC on Thursday she saw no reason to "give away" the veto power - which is intended to protect minorities - as her party felt "so strongly about the definition of marriage".
The DUP leader said that "very vicious" trolling online against her and party colleagues would "send me in the opposite direction and people need to reflect on that."
However, Mrs Long said "blaming online trolls" was inexcusable and blasted the DUP for "abusing the petition of concern to overturn what would be a democratic majority".
"It is not just childish and ill-fitting for the office that she holds, but actually is disingenuous because her party has, at every opportunity, sought to block any progress for the LGBT community in Northern Ireland," she said.
"By all means, if they don't agree with equal marriage they can vote against it.
"But I would hope that in a more mature democracy, that we could have seen some progress in terms of limiting the use, if not getting completely rid, of petitions of concern as a mechanism. So that we rely on simple democratic principle."
Speaking on the BBC Stephen Nolan show, the Sinn Fein MLA Caral Ni Chuilin added to the criticism.
"They're on the wrong side of history and public opinion on this issue. If someone told you you couldn't marry your partner because of how others feel, that's very hurtful," she said.