Downing Street needs to be more transparent over the evidence needed to call a referendum on uniting Ireland, an expert has said.
Professor Colin Harvey, a professor of Human Rights Law, has called for the UK to collaborate with Dublin to ensure voters are adequately prepared.
He wanted to avoid a repeat of the “mess” surrounding the Brexit poll.
He said: “There are some people on the island saying that the criteria have arguably been met electorally.
“The level of constitutional turbulence in the UK with what is going on in Scotland means we want to be prepared on this island for whatever eventualities emerge.
“That involves the British government being more transparent and both the British and Irish governments engaging well in advance and doing any preparation and planning before these votes take place.”
The member of Queen’s University School of Law predicted a referendum on unity within the next decade.
He added: “We do not want to repeat the Brexit mess and make sure we do the preparation and planning in advance so that when people vote they know what they are voting for.
“Both governments have a role in the process and doing the work in advance.”
He wrote to Northern Ireland secretary Brandon Lewis recently.
Lewis’ department wrote back: “The government is firmly committed to its obligations in this regard, including the circumstances set out in the Belfast (Good Friday) Agreement that require the secretary of state to hold a referendum on the constitutional status of Northern Ireland should a majority of those voting express a wish that Northern Ireland should cease to be part of the United Kingdom.
“The government, and the secretary of state for Northern Ireland, continue to monitor the full range of evidence on this issue.
“We engage with the Irish government on a regular basis regarding a range of important matters that have an all island of Ireland dimension.”
These discussions take place in accordance with the three stranded approach as set out in the Belfast (Good Friday) Agreement.
The NIO added: “The government is firmly of the view, however, there is no clear evidence that would suggest that the conditions for a referendum on a change to the constitutional status of Northern Ireland have been met at this time.”
It said the government has always stressed the importance of the Union and Northern Ireland’s place within it.
If at any time it appears likely to the secretary of state that a majority of those voting would express a wish that Northern Ireland should cease to be part of the United Kingdom, the secretary of state is then obliged to call a referendum.
The NIO added: “In making this judgment the secretary of state must have regard to reasonable factors and make a judgment based on objective, reliable and empirical information.
“The High Court, in a recent judicial review on this matter, agreed with the government that there is no legal requirement, or that it is in the public interest, for the government to set out a policy detailing fixed criteria on the holding of a referendum.”