Brexit: Drakeford would 'push back' on damaging UK-EU deal
The Welsh Government would try to "push back" on implementing any UK-EU trade deal it felt would damage the Welsh economy.
First Minister Mark Drakeford said they would not be "the agents of the UK government" if the new EU deal led to the "destruction" of major industries.
The UK government said it was committed to delivering a deal "that works for the whole of the UK".
Official post-Brexit talks between the UK and EU start in Brussels on Monday.
Prime Minister Boris Johnson has pledged to get a deal with the EU by the end of the "transition" period - 31 December 2020 - and has said he is not prepared to extend that deadline.
But the UK government has warned it will walk away from the talks in June unless there is a "broad outline" of a deal.
It has published a 30-page document outlining its priorities for the negotiations.
The document said ministers wanted a trading relationship with the EU based on its existing ones with Canada, Japan and South Korea.
Following the publication of the document, Mr Drakeford accused the UK government of "putting ideology ahead of people's livelihoods".
He added in a speech at Aberystwyth University on Thursday that "it would serve no-one's interests" if the UK government entered into a deal with the EU that the Welsh Government was "not prepared to implement".
Speaking on BBC Wales' Politics Wales programme, the first minister expanded, saying: "I was pointing to international evidence that shows that where you have a system like ours where the UK government can strike trade deals, and that is their prerogative.
'Won't be like that'
"But where the implementation of those trade deals falls to powers that they don't have, that lie in Wales, that lie in Scotland, that lie in Northern Ireland, the international evidence is that where trade deals are struck that can't easily be implemented at the local level those trade deals don't do what people expect of them.
"If this government struck a deal that, for example, meant the end of the sheep industry here in Wales or meant the end of the manufacturing industry here in Wales, they're not going to expect us to simply implement what would be the destruction of such vital parts of the Welsh economy."
Mr Drakeford said they would potentially "use the powers that we had to try to mitigate, to push back on" the implementation of the aspects of a new UK-EU deal that were the responsibility of the Welsh Government.
"But the idea that we are simply the agents of the UK government and if they say to us, 'close down that industry', that we will say, 'yeah, fine, let's get on with it' - it just won't be like that," he added.
In a statement released on Thursday, a UK government spokesman said: "We are committed to working with the devolved administrations to deliver a future relationship with the EU that works for the whole of the UK and strengthens the union.
"The approach to negotiations we have published today is a vision for a relationship based on friendly co-operation between the UK and EU.
"The people of Wales voted for the UK to recover its economic and political independence and we are delivering on that vote."