Sinn Fein and Social Democrats say they will back two Yes votes in the upcoming referenda.
Two referenda are to be held on March 8 to amend Ireland’s Constitution.
One will ask whether the definition of family should be based on “durable” relationships rather than on marriage (Article 41), and another will ask whether a reference to the role and duties of women in the home should be deleted and replaced with a new article on carers (Article 41.2 replaced with 42B).
Legislation to approve the referenda was debated in the Dail last week and is continuing to be heard in the Seanad this week.
A number of opposition parties have raised concerns about the proposed wording of the questions, including the meaning of the word “durable”.
Asked whether the party will back Yes votes, Sinn Fein TD Eoin O Broin said: “My understanding is yes. Obviously there are still some issues in terms of legislation, and we are supporting some of the opposition amendments as the legislation passes through the Seanad.
“But whatever about the final wording, and I know there is some debate about that, ultimately with respect to carers and also the outdated language about women in the home. There’s a job of work to be done to address those historic issues.
“So as it currently stands, the answer is yes.”
Social Democrats also confirmed it will campaign for Yes votes ahead of the referendum.
Wicklow TD Jennifer Whitmore said: “Obviously, there were some concerns in relation to the wording and whether the wording went far enough but I think, overall, it is a positive step and I think it is important to show support for those.
“We will be supporting both those referendums.”
However, Labour leader Ivana Bacik said her party will decide its position following meetings of the parliamentary party and the executive party this week.
Labour has tabled a number of amendments and also sought clarity from the Minister for Children, Roderic O’Gorman, about the meaning of the word “durable”.
Asked whether Labour will campaign for a Yes vote, Ms Bacik said: “We haven’t yet come to a decision as a parliamentary party or through the executive party.
“We have a parliamentary party meeting today and executive board (meeting) tomorrow, and we will wait and see what clarity the government can provide on definitions on durable through the course of debates.
“I am conscious the Seanad debate had not yet concluded and amendments are still live so we will make the decision this week.”
She added: “I wanted to thank Minister O’Gorman for clarifying issues that will come up, in particular the definition of a durable relationship and whether a family, based on a durable relationship is confined to a couple, which is what it is in European law.
“The minister very clearly outlined why the definition in the Constitution that he has proposed, that definition is beyond couples and also applies vertically, in other words between parents and children, by reference to Article 42 of the Constitution.
“I think as the Bill progresses through the Dail and Seanad I think people will engage more and more.”