The UK government's handling of Brexit talks has been "chaotic at best", according to Scotland's secretary for external affairs, Fiona Hyslop.
Relations between Westminster and the devolved administrations in Scotland and Wales during the UK's negotiations to leave the EU has "left a lot to be desired", she added.
The Scottish National Party minister told an audience at the Institute of International and European Affairs that the UK government had to adopt “a more inclusive approach” and open up Brexit negotiations to more parties and “all constituent parts of the United Kingdom”.
Ms Hyslop said the absence of a functioning political executive in Northern Ireland since the administration collapsed in January was "difficult in many obvious ways".
Having a Belfast administration "up and running as soon as possible would be of great help in overseeing the negotiations across the UK", she said.
Her visit marks the sixth by a Scottish government representative to Dublin in three months as part of Edinburgh’s push for the UK to remain in the EU single market and customs union post-Brexit.
Ms Hyslop expressed her frustration at the Conservative government’s lack of engagement on Brexit.
“The Scottish government has tried to be reasonable, constructive and prepared to compromise,” she said. “But I would warn that there are still political forces at play in Westminster who do not want to compromise. And there still remains a no deal risk which would be catastrophic for all of us.”
She criticised London's proposed EU withdrawal Bill, as it will retain powers over agriculture, fisheries and the environment devolved from Brussels post-Brexit at Westminster when they should move to Edinburgh.
The Bill “represents little more than a power grab by the UK curtailing devolution”, she said.
Unless there were significant changes to the Bill, the Edinburgh government would not recommend that the Scottish parliament consent to it.
This would “force us into uncharted political territory and undoubtedly has the potential to lead to a constitutional crisis”, she said.
Ms Hyslop said she hoped the UK “comes to its senses and works with the devolved administrations”.
The Scottish government recognised the “unique position” Ireland finds itself in as a result of Brexit, she said, and supported the Irish Government’s position that there should be no hard Border.
"A point that is apparently lost on far too many people in the United Kingdom is that the Irish Border is not just an economic boundary," she said. "It represents so much to anyone touched by the recent history of this island."