Sinn Féin introduced legislation in the Dáil on Tuesday that would establish a Citizens' Assembly to examine Irish unity. The proposed law also requires the Irish government to publish a Green Paper on preparations for constitutional change, covering areas such as the economy, health, and housing. It further obliges the Taoiseach to consult with unionist and Protestant representatives, civil society groups, and experts from all political traditions.

The Citizens' Assembly would consist of 99 randomly selected citizens and an expert moderator. It would discuss the practical steps toward a united Ireland and report its findings to the government. Previous assemblies in the Republic have addressed abortion law and drug policy.

The Irish government intends to oppose the bill. Instead, it will bring forward a counter-motion, which TDs will debate and vote on, rather than voting directly on Sinn Féin's proposal.

A large Sinn Féin delegation attended Leinster House to support the legislation, including Northern Ireland First Minister Michelle O'Neill, Stormont ministers, and MLAs.

Sinn Féin leader Mary Lou McDonald told reporters that a border poll is a matter of when, not if, and argued that preparations must begin now. She noted that for the first time, the first ministers of all devolved governments are nationalist, creating what she described as a timely window. McDonald also claimed that members of Fianna Fáil and Fine Gael in the Dáil recognise the need for planning and broadly support Irish unity.

Fine Gael separately confirmed it is developing its own blueprint for Irish unity, expected to be completed by November.