Mary Lou McDonald, the President of Sinn Féin, called for “a mature conversation on constitutional change” regarding Irish reunification during her keynote address at Sinn Féin's fringe meeting at the British Labour Party Conference in Liverpool on Sunday, September 22.

“Part of this new chapter must be the realization that constitutional change in Ireland is coming," McDonald said on Sunday.

"I am very aware that this is the subject of genuine conviction and opinions right across Irish society. It also stirs deep emotions for people.

“What is best for Ireland is that Britain ends its involvement in our affairs, and that the people of Ireland finally get to decide our future together.

"I believe that is what is best for Britain too.”

🇮🇪 Delighted to be in Liverpool tonight to deliver a major speech making the case for the reunification of Ireland and the holding of unity referendums by the end of this decade.

A new and united Ireland is for everyone. The conversation must include everyone. The future…

— Mary Lou McDonald (@MaryLouMcDonald) September 22, 2024

The morning after her keynote address, McDonald told Sky News: "We are hopeful, we anticipate, and we expect that Keir Starmer as Prime Minister that the whole administration will now come behind the Good Friday Agreement in its totality to bring the Irish story, the journey towards peace, to the next destination.

"And, of course, at the heart of the Good Friday Agreement, is a provision for referendums to end the partition of our island and, really, to complete the journey to equality and to peace."

McDonald said she hopes Starmer will "grasp this historic opportunity and I hope he, like I, would wish that when the history books record the Irish history and the final, full resolution of the Irish conflict that it might be a Labour Prime Minister who had the vision and the integrity to take these next steps with us."

Sky News pointed out that McDonald's optimism is at odds with Starmer's comments last year when he claimed an Irish unity referendum is "not even on the horizon."

However, after he became British Prime Minister in July, Starmer softened his approach slightly, saying that “the framework is set out and I’m absolutely committed to the Good Friday Agreement."

McDonald acknowledged on Monday that she is "forever optimistic," but "not naive."

She said as Prime Minister he, along with the British and Irish governments, are co-guarantors of the Good Friday Agreement and that "you can't cherry pick from it."

She said that the obligation to plan for the future and to plan for these referendums runs right alongside the "working together in the here and now."

She continued: We shouldn't stumble into this.

"With all due respect, we watched the manner in which the Brexit debate happened, and to us that was a case study on how not to do it."

McDonald went on to reiterate that she wants "preparation," "dialogue," and "mature conversation" amongst the people on the island of Ireland and "critically, between the Dublin and the London administrations."

She continued: "And by the way, this Irish story of finding peace and reunification is great news for all of us. This is right for Ireland, but I would submit right for Britain as well. It's right for the British people and the Irish people for us to live not just as good neighbors but I would hope, ultimately, as the very best of friends."

When asked if she expects Starmer to "promise the world" in regards to discussions on Irish unity, McDonald replied: "I'm not asking for the world. 

"We as Irish people are not asking for anything more or less than we are legally entitled to and nothing more or less than what's contained in the Good Friday Agreement.

“I didn’t invent this idea on my way into studio. This is a long-standing provision of an Agreement that is now 26 years old.

“And what I am saying I suppose, in summary, is that all parties to the Agreement now need to recognize the depth of change that is happening in Ireland.

“The Unionist majority in the North of Ireland, the electoral majority, is gone. It’s not coming back.

“We live in the now and we have to plan for the future.

“I am asking for, and we are promoting, dialogue, inclusion amongst all stakeholders of all perspectives.

“But there has to be clarity from the British government - and, by the way, the government in Dublin - that the referendum provisions of the Good Friday Agreement were not drafted to lie dormant but will, in fact, be enacted and that the people ultimately will have our say and decide our future together democratically and peacefully and in a spirit of respect, cooperation, and indeed friendship with Britain."

As per the Good Friday Agreement, Northern Ireland's Secretary of State has the power to call a border poll "if at any time it appears likely to him that a majority of those voting would express a wish that Northern Ireland should cease to be part of the United Kingdom and form part of a united Ireland."

McDonald noted while on Sky News that for the first time ever, Sinn Féin is the largest party in Northern Ireland and holds the office of First Minister.

Despite this, opinion polls have not found overwhelming support for a border poll. In February, a LucidTalk poll for the Belfast Telegraph found that 49% of respondents in Northern Ireland would vote to remain in the UK if a border poll was held within a week, while 39% would vote to leave the UK and join Ireland.

However, in Ireland, the Joint Oireachtas Committee on the Implementation of the Good Friday Agreement said in July that preparation for referenda on Irish unification will be "a historic task" and called for "preparation to begin immediately."