The Welsh government has left Nicola Sturgeon unexpectedly isolated after agreeing to sign a controversial deal with UK ministers over the sharing of EU powers after Brexit.
Mark Drakeford, the Welsh finance secretary, said significant concessions the UK government had made in the last few days were enough to protect the Welsh assembly’s powers when Britain leaves the EU.
That signals the end of a potent coalition forged last year between Scotland’s first minister and her Welsh counterpart Carwyn Jones when they united last year to accuse London of plotting an unjustifiable power grab after Brexit.
Shortly before Drakeford’s announcement, Sturgeon had written to Theresa May stating that the Scottish government remained opposed to the proposed power-sharing deal, and would not yet sign it.
In an open letter published on Tuesday afternoon, she pressed the prime minister to make further concessions on how their two governments would share powers, which include farm subsidies, fishing quotas, GM crop policies, organ transplant rules and food labelling.
The Welsh agreement means the Cabinet Office can now table its detailed amendment to the EU withdrawal bill on devolution powers in the House of Lords before a deadline of 4pm on Wednesday.
Scottish and UK ministers will hold a further, potentially decisive round of talks next week.
Welsh support for the deal suggests peers will be less willing to support Scottish demands for greater concessions when the Lords debates the new clause next week, and when they vote on it later in May.
The joint approach by Sturgeon and Jones, who is standing down in the autumn, backed publicly by the Scottish Tories, had forced May into making a series of substantial concessions on their post-Brexit powers earlier this year. May gave the Scottish and Welsh legislatures direct control over more than 100 policy areas currently controlled by the EU.