Ysgrifennodd Prif Weinidog Cymru at Brif Weinidog y DU ym mis Mai gan nodi ei bryderon y byddai unrhyw gynigion i ddatgymhwyso rhannau o Brotocol Gogledd Iwerddon yn unochrog yn peri risg o niwed gwirioneddol i economi Prydain.
The First Minister wrote to the Prime Minister in May setting out his concerns that any proposals to disapply unilaterally parts of the Northern Ireland Protocol would “risk material damage to the British economy”.