Trade versus constitution post-Brexit
Alun Cairns has framed this debate in terms of trade and the constitution, and more specifically around the question of what should come first.
The Welsh Government believes it is an outrage that EU powers in devolved areas will be heading in the direction of Westminster, rather than Cardiff, after Brexit.
Alun Cairns believes that would take too long, and in order for trade to continue with the rest of the EU the morning after we leave, there needs to be a quick way of dumping all the Brussels rules and regulations into a temporary Westminster "holding pattern".
The calculation is that farmers and steelworkers will agree that uninterrupted trade with some of their biggest customers will outrank the constitutional niceties of the devolution settlement.
In the end, this standoff comes down to trust. The Welsh Government is being asked to trust the UK Government that it is a temporary arrangement. It would appear that trust is in short supply.
UK Government sources in Wales tell me the angry tone of the Welsh Government's response is "completely different" to the reality of the negotiations behind the scenes between the officials from both governments.
The accusation is that the first minister is grand-standing in Brussels, the response is a scathing statement accusing the UK Government of astounding ignorance, and a crude power grab.
So where does it go from here? The question is whether the UK Government is prepared to make a concession on the holding pattern, which is a central part of the repeal bill, and something which it has been unwilling to touch so far.
One possibility could be what's called a "sunset clause", or deadline in which a specific and limited time-frame for the temporary arrangement of say two years is set out in legislation.
Alun Cairns acknowledges it sounds sensible but in reality removes the incentives for any of the parties to strike a deal because they know if nothing is agreed within the time-frame then it will collapse.
Of course this is just one of the problems facing the UK Government as it looks to head off any rebellions with a slim majority when the proposed legislation is debated and voted on in the Commons in the autumn.
And there is also the possibility of a transitional deal for the UK after Brexit which could buy ministers some breathing space in order to put together a new plan which everyone can agree on.