PEERS have tabled changes to the UK Government’s Brexit Bill to avoid a “constitutional collision” and establish a system that could seek to mediate disputes between London and Edinburgh over the proposed common frameworks.

Earlier this week, Nicola Sturgeon and Theresa May sat around the Downing Street table to try to resolve the deadlock facing the flagship EU Withdrawal Bill.

The First Minister and her Welsh counterpart, Carwyn Jones, believe the legislation is a “power-grab” because not all of the 100-plus powers and responsibilities post-Brexit will go directly to Edinburgh and Cardiff.

They have written a joint letter to Lord Fowler, the Lords Speaker, suggesting amendments that require the consent of the Scottish Parliament and Welsh Assembly for any temporary restrictions on devolution, including a sunset clause, and that any future primary legislation at Westminster would need the consent of the devolved parliaments.

Ms Sturgeon and Mr Jones add: “The two Governments have also asked that the UK Government agree a level playing field and make a commitment not to bring forward legislation in respect of England in those areas where it is agreed common frameworks are to be established.”

The UK Government wants to hold back some 24, covering such things as agriculture, fisheries, food standards and environmental protection, so that common frameworks can be agreed to protect the country’s internal market.

Ms Sturgeon emerged from the latest meeting of the Joint Ministerial Committee in an unexpectedly optimistic mood, saying that while the differences between her and Mrs May were not insignificant, nor were they “insurmountable,” and that with a deal of goodwill and determination an agreement could be reached.

Tory peer Lord Mackay of Clashfern and Labour peer Lord Foulkes of Cumnock have tabled amendments to seek to set up a mediation structure to get round disagreements on the frameworks.

Lord Mackay calls for the establishment of a frameworks group of ministers from the three governments as well as a senior official from the Northern Ireland Office.

Crucially, if the group cannot come to agreement on any “undecided issues,” then it would be up to Westminster to decide ie, in normal circumstances, the UK Government.

Lord Foulkes’s amendment is similar but allows for the “withdrawal arrangements ministerial council” to comprise of the Prime Minister and the FM. If they cannot decide, then decisions would go to another body: an advisory council but its recommendations would have to be adopted by a simple majority of the council.

“At the moment, we are on a constitutional collision course,” said Lord Foulkes. “The amendments are our attempts to get round the impasse and find a way forward.”

When it was pointed out that seeking a simple majority on a council of four members could result in stalemate, the former Scotland Office Minister replied: “I’m not saying this is an ideal solution; like the bill itself it can be changed.”

Downing Street said that no more JMCs were planned and that officials from London, Edinburgh and Cardiff would continue to meet to try to resolve the deadlock. But Alun Cairns, the Welsh Secretary, following this week’s JMC suggested a solution was getting “closer”.

The bill sees the last of its 10 days of Committee Stage in the House of Lords a week on Monday and, following the Easter break, will go into six days of Report Stage, taking the deadline to get a resolution into May.

It will be then that either there is a resolution or the bill will have to proceed without the consent of MSPs and AMs and all the constitutional consequences that that implies.