The Northern Ireland Secretary has appeared to rule out calling a border poll in the immediate aftermath of an historic Stormont election.

Sinn Fein became the first nationalist or republican party to become the largest in the Northern Ireland Assembly with 27 seats, ahead of the DUP on 25.

There was also a significant surge in support for Alliance who are now the third largest party at Stormont with 17 seats.

Sinn Fein can now nominate a first minister who will be the first from a nationalist or republican party.

However they cannot do so under the current rules unless the DUP nominate a deputy first minister to serve alongside in the joint top office.

Sinn Fein president Mary Lou McDonald earlier raised the prospect of a border poll within the next five years.

On Sunday, she told BBC Radio 4’s The World This Weekend she wants to a see an Ireland-wide citizens’ assembly to “plan for change”.

“The only one clear demand that I have made consistently for the last number of years is that preparation for constitutional change needed to start,” she said.

The Secretary of State has the power to call a border poll.

Brandon Lewis was questioned on BBC Northern Ireland’s Sunday Politics programme on the criteria for him calling a border poll.

He responded by saying the nationalist vote has not gone up, and the unionist vote remains higher.

“Sinn Fein haven’t gained seats, we haven’t seen a growth in the nationalist vote and indeed the unionist vote is still larger and the number of seats held by unionist parties is still larger,” he said.

“I think the focus at the moment quite rightly is on getting Stormont back up and running, getting the money that is moving from the UK Government to Northern Ireland out to people in Northern Ireland so we can move forward on domestic issues, get the healthcare reform that people want to see and we want to get the protocol resolved for everyone in Northern Ireland.”

He described the prospect of the first nationalist first minister as a “significant moment for Northern Ireland”.

“I think it’s an important moment to show that everyone can work together regardless of who is first and deputy first minister, that’s what democracy is about and why it’s important,” he said.

“It’s been also significant seeing that shift and that move for people who have been voting for the Alliance Party over the last few days.”

Labour’s shadow Northern Ireland secretary Peter Kyle said a border poll is “some way off”.

“Only a third of people, about 32%, in Northern Ireland do support a border poll,” he told LBC. “So this is some way off. And people have said very, very clearly in this election in Northern Ireland that the priority is the cost-of-living challenge.

“Second priority is getting public services improved, and other areas of public life sorted out. So those are the priorities now.”