The Brexit Secretary David Davis has clarified the government's view on Northern Ireland's status within the European Union, in the event of a future border poll in favour of a united Ireland.
He said that should the people of Northern Ireland vote to leave the UK, they would "be in a position of becoming part of an existing EU member state, rather than seeking to join the EU as a new independent state".
Mr Davis made the remarks in a letter to the SDLP MP Mark Durkan.
'Principle of consent'
The Social Democratic and Labour Party is an Irish nationalist party that campaigned for the UK to remain in the EU in last year's referendum.
Mr Durkan had asked the Brexit secretary about Northern Ireland's ability to become part of the EU, under the consent provisions of the 1998 Belfast Agreement, also known as the Good Friday Agreement.
Mr Davis replied that the Westminster government was "committed to the principle of consent enshrined in the Belfast Agreement, which makes clear that Northern Ireland's constitutional position is a matter for the people of Northern Ireland to determine".
He added: "If a majority of the people of Northern Ireland were ever to vote to become part of a united Ireland, the UK government will honour its commitment in the Belfast Agreement to enable that to happen.
"In that event, Northern Ireland would be in a position of becoming part of an existing EU member state, rather than seeking to join the EU as a new independent state."
The Brexit secretary added it would then be up to the EU Commission "to respond to any specific questions about the procedural requirements for that to happen".
However, Mr Davis told Mr Durkan that the government's "clear position is to support Northern Ireland's current constitutional status: as part of the UK, but with strong links to Ireland".
Previously, Taoiseach (Irish Prime Minister) Enda Kenny suggested that any overall deal on Brexit should clarify the right of Northern Ireland to automatically join the EU in the event of a vote for Irish unity.
An example often cited has been that of East Germany, which became a member of the EU after reuniting with West Germany.