Nicola Sturgeon has joined with Welsh First Minister Carwyn Jones to call on Theresa May to think again about pulling the UK out of the single market and customs union.

In a joint statement, the Scottish and Welsh leaders said quitting was not in the national interest and urged the prime minister to secure a Norway-style solution in the EU exit talks.

The call comes ahead of a meeting of the British-Irish Council (BIC) in Guernsey on Friday, which will bring the leaders together with Mrs May's deputy, David Lidington, and Irish Prime Minister Leo Varadkar.

Mr Lidington insisted the UK Government was committed to maintaining a good working relationship with the devolved administrations despite the "inevitable political noise" over Brexit and urged the Scottish Government "to maintain their own side of that relationship".

Ms Sturgeon and Mr Jones said the European Union had been "very clear" that the UK Government's red lines meant the "only Brexit on offer is one which will deeply damage our economies and possibly jeopardise our security".

They said: "In practice, the Prime Minister's position on issues such as customs arrangements and regulatory alignment appears increasingly difficult to reconcile with the red lines, but she cannot come clean because she is held hostage by the Brexiteers in her Cabinet and party. This cannot continue.

"We call on the UK Government in its forthcoming white paper to commit to staying inside the single market and customs union recognising that this will require continued alignment with the EU regulatory environment."

Relations between Westminster and Holyrood have become increasingly strained over Brexit.

SNP MPs staged a Commons walkout in protest over the way the EU (Withdrawal) Bill had been dealt with and Ms Sturgeon said Scotland had been "treated with utter contempt".

Mr Lidington said voters expected the governments across the UK to work together and highlighted how Scotland had voted to remain part of the Union.

The BIC brings together representatives of the Irish and British governments, the devolved administrations in Northern Ireland, Scotland and Wales and the Isle of Man, Guernsey and Jersey crown dependencies.

The council will also discuss the current political situation in Northern Ireland and Mr Varadkar is expected to reiterate his regret that Northern Ireland has no representation because the Executive has still not been restored.