Northern Ireland’s new first minister has told Sky News she “absolutely contests” the UK government’s claim that a referendum on Irish unity is decades away.

Sinn Fein’s Michelle O’Neill, the first nationalist to occupy the office, described her elevation at Stormont as “a historic day, truly representing a new dawn”.

In a document, outlining the basis of the DUP’s return to power-sharing, the UK government said it saw “no realistic prospect of a border poll”.

But Ms O’Neill said: “I would absolutely contest what the British government have said in that document, in so far as my election to the post of first minister demonstrates the change that’s happening on this island.

“That’s a good thing. It’s a healthy thing because this change I think can benefit us all.

“I believe that we’re in the decade of opportunity and I believe, also equally, that we can do two things at once.

“We can have power-sharing, we can make it stable, we can work together every day in terms of public services, and whilst we also pursue our equally legitimate aspirations.

“There are so many things that are changing. All the old norms, the nature of this state, the fact that a nationalist republican was never supposed to be first minister. That all speaks to the change,” she added.

Ms O’Neill grew up in the “murder triangle” in County Tyrone. Her father was an IRA prisoner and her cousin was shot dead by the SAS.

But having pledged to be a “first minister for all”, she broke with republican tradition by using the term “Northern Ireland” in her acceptance speech.

“I’m somebody who wants to be a unifier. I’m somebody that wants to bring people together.

“We’ve had a difficult past, a turbulent past. A lot of harm was caused in the past and I think it’s so, so important that here in 2024, and we’ve just celebrated the anniversary of the Good Friday Agreement last year, that we very much look towards the future.

“I hope I can represent the future. I believe I can represent the future, as somebody who wants to work with all communities.

“I obviously am a republican, a proud republican, but I think it’s really, really important that I can look towards those people who identify as Irish republicans, but also those of a British identity and unionist identity and tell them that I respect their values, I respect their culture.”

Asked if her pledge meant she would consider attending a Protestant Orange Order march, she said: “I will consider every invitation that comes my way.

“I’m hoping that I get invitations. I want to step into ground that republicanism hasn’t stepped into before,” she added.

Watch the full interview with Michelle O’Neill on Sunday Morning With Trevor Phillips on Sky News from 8.30am.