Brexit an opportunity to reinvent the UK - Carwyn Jones
Brexit provides an opportunity to "reinvent and strengthen" the United Kingdom, Wales' First Minister Carwyn Jones has said in a speech in Cardiff.
He unveiled a blueprint for an overhaul of relations between the governments of the four nations after the UK leaves the European Union.
A new UK Council of Ministers would settle post-Brexit power disputes.
Mr Jones called on the UK nations to work together "through discussion, not diktat, to map our collective future".
The first minister has already written to Prime Minister Theresa May urging her to rethink plans for a hard Brexit, saying she had "no mandate" for it after the Conservatives lost their majority in the snap election she called hoping to strengthen her position.
Speaking at Cardiff University on Thursday, Mr Jones re-stated his preference for securing "full and unfettered access" to the EU single market after Brexit, and stressed the need for co-operation to find a way forward.
He described leaving the European Union as "the biggest challenge facing the United Kingdom, a challenge thrown into even sharper relief by the outcome of the general election".
It will influence "our ability to trade, travel, attract investment, determine policies, legislate, support our countryside, invest in our regions", Mr Jones added.
He warned the "fallout" from Brexit had "the potential to destabilise the United Kingdom as we know it - or, if we work together, we can use this as an opportunity to reinvent and strengthen our union".
The proposed UK Council of Ministers would take over from the current Joint Ministerial Council, through which the UK government has heard the Brexit priorities of the devolved administrations in Scotland, Wales and Northern Ireland.
Mr Jones said: "The Joint Ministerial Council is a talking shop.
"Sometimes it becomes a shouting match."
An updated white paper from Mr Jones also called for a convention looking at the wider questions about the future of the UK once it leaves the EU.
"The opportunities presented by EU exit must be about the future, not the past - and that is what our paper is about," he said.
"It represents an important step forward in the work which we must undertake together with England, Scotland and Northern Ireland - through discussion, not diktat - to map our collective future."
A UK government spokeswoman said it was "committed to working with the devolved administrations to ensure we deliver a deal that works for the whole of the UK".
UK ministers were "going further than ever before in implementing historic changes to how Wales is governed through the Wales Act 2017", she added.
"It is a settlement that will stand the test of time and delivers a clearer, stronger and fairer devolution settlement for Wales."
Welsh Conservative leader Andrew RT Davies said: "It is a welcome but curious thing to hear the first minister talking about the opportunities of Brexit, given that his language on the issue has to date been couched in near consistent negativity."