People in parts of the UK with high rates of Covid-19 will be banned from travelling to Wales under plans announced by Wales’ first minister.
Mark Drakeford said he would go ahead if the prime minister did not impose travel restrictions in England.
It is expected the ban will cover all of Northern Ireland, England’s tier two and three areas and the Scottish central belt.
The UK government said the decision was “disappointing”.
And the head of the Police Federation in Wales warned the rules could be “unenforceable”.
“There will also be plenty of individuals travelling legitimately from areas which are not high risk, and this will only add to the other difficulties officers face when policing the existing regulations,” Mark Bleasdale said.
Scotland’s First Minister Nicola Sturgeon said she fully supported Mr Drakeford’s move.
She said she would write to the prime minister seeking urgent talks over UK-wide travel restrictions and called for a “sensible agreement” between the four nations.
Mr Drakeford had written twice in recent weeks to Boris Johnson asking for travel to be restricted in and out of areas with high levels of transmission in England.
The UK government has repeatedly refused to do so, instead asking people in the Liverpool City Region to avoid non-essential travel.
UK government ministers plan to write to Mr Drakeford to raise their concerns about the travel ban and some of the language being used, BBC Wales has been told.