Ireland has to prepare for the change that's coming in a united Ireland referendum.
That's according to John O'Dowd, who was re-elected to Stormont as an MLA over the weekend.
His party has become the largest in Northern Ireland for the first time, beating the DUP by two seats.
As such it is entitled to nominate Michelle O'Neill as the region's first nationalist First Minister.
Britain's Northern Ireland Secretary Brandon Lewis is to hold talks with the political parties there on Monday, urging them to restore power-sharing quickly.
However the DUP has refused to say if it will nominate a person to the Deputy First Minister position.
While Sinn Féin leader Mary Lou McDonald has said she wants to see a border poll on Irish unity within the next five years.
Mr O'Dowd told Newstalk Breakfast the island needs to prepare for the referendum, regardless of the outcome.
"What we need to do is prepare for that border poll.
"And whether Sinn Féin's talking about this or not, and we are talking about it, the conversation about constitutional change is taking place across the island of Ireland in different settings and different political groupings.
"Because people realise constitutional change is going to happen within a timeframe in the near future.
"So let's prepare for it - let's recognise the mistake that was made around Brexit, where a referendum was held without any preparation.
"Any referendum from your differing perspectives can be lost, but let's prepare for the change that is coming.
"Let's give a structure to the conversation that is taking place across the island of Ireland.
"And let everyone who has a stakehold on this island come together and discuss what the constitutional future of this island will look like".
DUP 'need a reality check'
On forming a Stormont executive, he says this is the only way to help people.
"From our point of view it's back to the executive, get executive ministers in position, have a fully functioning executive and start dealing with the problems that workers and families are facing.
"Only a fully functioning executive can help people, and that's what the people asked for during the election campaign."
Asked about any DUP resistance, particularly without changes to the Northern Ireland Protocol as a result of Brexit, he says the unionist party promised more.
"The DUP stood on a five-point manifesto - one of those was around the protocol.
"But there was also, within that manifesto, calls for help for people with the cost of living, to shorten the waiting lists in terms of the health service.
"And they're not going to be able to achieve any of those things without a fully functioning executive.
"So there's no point in the DUP punishing ordinary workers and families because the British government has once again let them down, or because they're in some sort of dispute with the European Union.
"Neither of those two things can be resolved by the assembly or by the people who voted in significant numbers for parties who want the executive to return.
"So the DUP need to have a reality check and need to come back into the executive".
And he says the DUP has to decide whether it respects the democratic will of the people.
"I do think there is a view among many nationalists that the DUP are not prepared to share power with their nationalist and republican neighbours.
"And they most certainly aren't prepared to accept a nationalist First Minister - but they're either democrats or they're not.
"So the DUP have to step up to the mark; and there's a responsibility on the Irish Government, the British government - and indeed the international community - to ensure that the democratic outcome of an election is upheld".
