Britain's Northern Ireland Secretary, Brandon Lewis, has expressed his surprise at comments from Tánaiste Leo Varadkar that a united Ireland could happen in his lifetime.
Mr Lewis also suggested in the UK House of Commons that the comments could be explained because of the success of Sinn Féin in opinion polls in the Republic.
Mr Varadkar told the Fine Gael Ard Fheis on Tuesday that Irish reunification should be the party’s “mission”, and he called for an increase in engagement with communities in Northern Ireland.
Mr Varadkar said the “tectonic plates were shifting” in the region and called for his party to establish a branch across the border.
He said: “It means the unification of the people of our island as well as territory of Ireland and it is a legitimate political aspiration.
“We should be proud to say that unification is something we aspire to. It should be part of our mission as a party to work towards it.”
The comments were raised at Northern Ireland questions in the Commons by DUP MP Gavin Robinson.
Mr Robinson said: “Can I ask the Secretary of State what reflections he has to make on the deeply unhelpful and destabilising contribution from the Irish Tánaiste yesterday at such a grave time of political instability in Northern Ireland?”
Mr Lewis replied: “I join the honourable gentleman in some surprise at the comments we saw yesterday.
“We would be concerned about any deviation from the principle of consent as enshrined in the Belfast Good Friday Agreement, but that agreement of course does respect the right of anyone to express their views and we fully support that.
“We do note the recent Life and Times survey which has support for a united Ireland at a low of 30 per cent in Northern Ireland.
“I also am aware of the polls which put Sinn Féin ahead in the Republic, which may explain the timing of some of these comments from the Tánaiste.
“I would urge everyone to dial down any rhetoric, particularly at this time of year, I think it is unhelpful and ill-advised.
“Whatever the circumstances, this Government will support the principle of consent and all of our obligations under the Belfast Good Friday Agreement.”