Carwyn Jones has joined forces with the Scottish First Minister to publish a list of proposed changes to the UK Government's main Brexit Bill.
The two First Ministers have also written to Theresa May urging her to work with the devolved governments to overcome their objections to her plans to transfer EU laws and regulations when the UK leaves.
They've previously expressed concerns about the Repeal Bill, also known as the EU (Withdrawal) Bill, saying that it amounts to a 'naked power grab.'
They say that powers in devolved areas like fishing and agriculture should be transferred to Cardiff and Edinburgh rather than London.
The UK Government insists that most powers will be devolved but some need to be administered on a UK-wide basis.
Speaking as the Welsh and Scottish amendments were published, Carwyn Jones said,
Last week Carwyn Jones and Nicola Sturgeon formally began the process of denying consent to the Bill in the Assembly and the Scottish Parliament by tabling Legislative Consent Motions at the same time as recommending that consent be denied.
However, in their letter, the First Ministers say that if the amendments are made, 'we could consider recommending to the Scottish Parliament and the National Assembly for Wales.'
They say their amendments have four aims:
- After leaving the EU, that powers in devolved policy areas are returned to the Assembly and Scottish Parliament
- Preventing UK ministers changing laws relating to devolution without the support of the devolved institutions
- Require the agreement of the Welsh and Scottish Governmenst on any changes to current EU laws in devolved areas after Brexit
- Ensure ministers in devolved governments aren't faced with greater restrictions than UK Government ministers.
Scotland's Brexit minister Michael Russell said the move by the First Ministers puts the ball into the UK Government's court.
The First Secretary of State, Damian Green, responded to the publication by promising to work with both governments.
But he warned that the UK Government will do nothing to risk the benefits of a United Kingdom and said that the Brexit process will leave devolved governments with more power than they have currently.