The SNP government, lead by Nicola Sturgeon, and the Welsh administration lead by Carwyn Jones, hope that the UK will stay within the single market and the EU customs union after Brexit in 2019

Nicola Sturgeon is working with the leader of the Irish government to block Theresa May’s proposals to leave the EU single market and customs union.

The alliance, which also includes Carwyn Jones, the Welsh first minister, was revealed yesterday by Leo Varadkar, the Irish prime minister, as he gave a scathing critique of the UK government’s Brexit plans.

Mr Varadkar has promised Edinburgh and Cardiff that he will push at European Council level “to try to keep the door open” for Britain to stay in the customs union and the single market, or to draft a new free trade agreement that would be similar to the existing situation.

A Scottish government spokesman confirmed last night that Ms Sturgeon had an “introductory” call with Mr Varadkar