The UK faces a "full-blown constitutional crisis" unless all nations of the UK agree on the Government's approach to Brexit, a leading think tank has warned.
In a message to Theresa May as she hosts the leaders of the devolved administrations for talks, the Institute for Government (IfG) said the four governments should agree the "core planks" of the UK's negotiating position before the Prime Minister triggers Article 50, formally starting the Brexit process.
The IfG warned that imposing a Brexit settlement on Scotland, Wales and Northern Ireland may be legally possible but it would be a "reckless strategy" which could lead to the possible break-up of the UK.
The report acknowledged the difficulties that will be faced in reaching consensus between Mrs May, Scottish First Minister Nicola Sturgeon, Welsh leader Carwyn Jones and Northern Ireland's Arlene Foster and her deputy Martin McGuinness, but warned of a "serious breakdown in relations" if agreement was not reached.
"There is little common ground between these leaders on the future of the UK or almost anything else," the report said.
"So, as with the dog walking on its hind legs, perhaps we should be impressed if the four governments work together at all rather than overly critical of how skilfully they perform the task.
"But the stakes are high. If it proves impossible to find consensus and the dog topples over after a few tentative steps, the result may be a serious breakdown in relations between the four governments (and nations) of the UK."
The three devolved governments would "almost certainly" seek to vote on whether to give consent to the terms of Brexit, the report said.
Although the UK Parliament is sovereign and it would therefore be legally possible to ignore the views of Holyrood, Cardiff Bay and Stormont, this would be a "reckless strategy for a government committed to the Union, since it would seriously undermine relationships between the four governments, and increase the chances of Scottish independence and rifts in Northern Ireland's fragile power-sharing arrangements".
