Ms McAleese will attend an event for LGBT young people in Dublin and is expected to be joined by her son Justin, who only last month spoke publicly for the first time about growing up as a gay man.
Last month, his mother called the referendum a “human rights issue” and said it was about the future of Ireland’s children.
Organisers linked to the BeLonG To event confirmed that Ms McAleese’s involvement and appearance with yes campaigners on Tuesday —just three days before polling day — was a “significant intervention”.
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Meanwhile, one of the lesser known differences between marriage and civil partnership could raise problems come polling day.
The Department of Environment, Community, and Local Government has confirmed that any voter attempting to use their civil partnership cert as proof of identification when casting their ballot may not be allowed to vote.
Any married couple, however, can use their certificate as proof of identification.
A department spokesperson confirmed that a marriage certificate can be used as proof as long as it is accompanied by a further document which establishes the address of the holder is within the constituency.
Laws governing valid forms of identification at polling booths does not permit the use of civil partnership certificates, however.
Yes Equality spokesperson Gráinne Healy said that campaigners for a no vote have claimed civil partnership is enough for Ireland’s lesbian and gay citizens.
“My civil partnership certificate does not even gain me access to my local polling station in St Vincent’s Primary School in Glasnevin, where I will cast my vote,” said Ms Healy. “A small detail perhaps, but a detail that says a great deal about the esteem in which civil partnership is held in our law.”