Sturgeon urges May to 'face down hard-line Brexiteers'
Nicola Sturgeon has urged Theresa May to "face down the hard-line Brexiteers in her cabinet" and come to a "common sense" position on the customs union.
The prime minister is gathering her cabinet at Chequers to thrash out its stance on future relations with the EU.
Scottish ministers have put forward suggestions for the White Paper, to be published after the summit.
And the first minister urged Mrs May to back remaining in the EU customs union instead of an "unworkable" alternative.
Mrs May's inner circle is to gather at her country retreat on Friday in a bid to agree a position on Brexit and solve splits over future trading arrangements.
'Best of both worlds'
The plan is for the summit to sign off a White Paper of proposals for the UK's future relationship with the EU, which can then be put to European leaders.
Mrs May is putting forward a "best of both worlds" plan which No 10 insists will offer friction-free trade with the EU and the scope for the UK to strike trade deals elsewhere.
But leading Brexiteers have spoken out against the plan, with Jabob Rees-Mogg saying that keeping close alignment to EU rules and regulations would be a "really foolish policy".
Ms Sturgeon also hit out at the latest plans, saying the UK should instead seek to simply remain in the existing customs union.
The first minister said: "It looks as if it has taken two completely incredible and undeliverable plans and put them together to pretend it's something new and more workable.
"The EU has already said that these plans are unworkable, and instead of trying to create elaborate new procedures that nobody really thinks are practical, the best thing is to say we'll stay in the existing customs union.
"I hope Theresa May really does face down the hard-line Brexiteers in her cabinet and gets to a position that's one of common sense."
Mrs May has rejected calls to "pick a side" between Remainers and Brexiteers, saying: "I have picked the side of the British people and these are the ones for whom I will deliver."
Relations between the Scottish and UK governments have become increasingly strained over Brexit, particularly since Westminster passed the EU Withdrawal Bill without Holyrood's devolved consent.
The two governments have failed to come to an agreement over how powers currently exercised from Brussels should be used after the UK leaves the European Union in March 2019.
The row came to a head when only minutes were left for discussion of clauses pertaining to devolution in the final Westminster debates on the bill, with SNP MPs walking out of prime minister's questions in protest the following day.
It will also see the two governments face off in the Supreme Court later in July, with judges to hear a challenge against Holyrood's own Brexit bill from UK law officers.
Despite the row - which has continued with the Scottish government indicating it will not back devolved consent for any Brexit legislation - ministers have continued to meet and discuss Brexit and its implications.
A joint ministerial council (JMC) meeting on Thursday brought together Cabinet Office minister David Lidington with Scottish Constitution Secretary Mike Russell and Welsh Finance Secretary Mark Drakeford.
Ahead of the meeting, the Scottish government sent a paper of proposals for the Brexit White Paper to their London counterparts.
Mr Russell said the plans - previously articulated through the Scotland's Place in Europe paper and other Scottish government reports - were "realistic and workable".
He said: "We continue to make the case for continued membership of the European single market and the customs union as a compromise that respects the democratic decision of both Scotland and other parts of the UK."
Scottish Secretary David Mundell said the document was "constructive", and said he would make sure the Scottish government's position was made clear at the Chequers summit.
And Mr Lidington said a "significant amount" had been achieved through the regular JMC meetings between ministers.
He added: "The last JMC meeting was only a couple of weeks ago but today's meeting is an important point for us to take stock with the Scottish and Welsh governments.
"We are determined to get the best possible Brexit deal for all parts of the UK. This is a good opportunity for those of us in the UK cabinet to hear what the devolved governments have to say."