May rejects NI border poll after Sinn Fein calls for Irish unity vote

British prime minister Theresa May has responded quickly and abruptly to calls for a referendum on Northern Ireland's membership of the United Kingdom, rejecting the idea outright.

On Monday, Sinn Fein leader Michelle O'Neill said that the fallout from Britain's exit from the European Union would be a "disaster" for NI, and called for a border poll "as soon as possible".

During a debate in the House of Commons on Tuesday, May said the focus for the only isolated region of the UK should be on returning to government after a turbulent few months which culminated in a snap election earlier this month.

"The Secretary of State for Northern Ireland has looked at this issue," said May. "It is not right to have a border poll at this stage."

"What we should all be focusing on is bringing the parties together to ensure that we can continue to see the devolved administration in Northern Ireland working, as it has done, in the interests of the people of Northern Ireland."

O'Neill replaced Martin McGuinness as leader of the nationalist party in January after McGuinness' resignation brought down the Northern Ireland Assembly. She said that Brexit would have an overly adverse affect on stability in NI.

"Brexit will be a disaster for the economy, and a disaster for the people of Ireland. A referendum on Irish unity has to happen as soon a possible," she said.

A majority of voters in Northern Ireland voted to Remain in the UK in last June's referendum, with just under 56% opting to stay in the bloc, but the UK as a whole voted to Leave.