Despite Scottish and Welsh dismay at the draft text of the repeal bill, as a matter of law, the Scottish Parliament and National Assembly for Wales cannot block the passage of the bill by withholding their consent.
The bill would allow Westminster to convert EU law into UK domestic law in the UK. But the devolution legislation is unambiguous: the conferral of law making powers to Edinburgh, Cardiff and Belfast 'does not affect' the power of the parliament of the UK to make laws for Scotland, Wales and Northern Ireland.
So even if one of the devolved legislatures were to withhold consent, the Westminster parliament could still enact the bill.
The question of the devolved legislatures' consent arises because of the 'Sewel convention' '“ a political rather than a legal rule '“ whereby the UK parliament will not normally legislate with regard to devolved matters without the consent of the devolved legislatures. The convention takes its name from Lord Sewel, former minister of state in the Scottish Office, who 'announced' the convention during the parliamentary debates on the Scotland Bill in 1998.
After Scotland's 2014 independence referendum, the Sewel convention was put on a statutory footing in Scotland and later Wales. It has not been put on a statutory footing in Northern Ireland.
In the case brought by Gina Miller in 2016 over whether the government or parliament had the power to trigger Article 50 to begin the UK's withdrawal from the EU, the UK Supreme Court held that this statutory recognition did not signify any change in the convention's status. Its application is therefore a matter for the political process rather than the courts.
The UK government accepts that the Sewel convention applies to the repeal bill. In all such cases, the convention has been scrupulously observed by successive UK governments since devolution almost 20 years ago. Although the UK government could in theory disregard it by pushing through the bill without Scottish and Welsh legislative consent, it is unlikely to want to do so as it would lay itself open to the charge of acting unconstitutionally. In Scotland, it would also risk strengthening the case for a second independence referendum.
The parliamentary arithmetic in any event points in the same direction. To be able to proceed without the devolved legislatures' consent, the UK government would need to be confident of a majority in the House of Commons, which cannot currently be guaranteed. The search will therefore be on in the coming weeks for some form of agreement whereby their consent can be secured.
The devolved legislatures cannot block the bill but the need for their consent means that they have a considerable degree of leverage '“ much more so than if Theresa May had secured a landslide majority in the June election. It is likely the devolved nations will seek to exploit this leverage to the full.
Alan Page is Professor of Public Law, University of Dundee
Richard Wyn Jones, Professor of Welsh Politics and Director, Wales Governance Centre, University of Cardiff
There are few phrases more over-worked by journalists and commentators than 'constitutional crisis'. Nonetheless, the now very real possibility that the devolved legislatures in Cardiff and Edinburgh will refuse to give their consent to the European Union (Withdrawal) Bill '“ the legislation formerly known as the Great Repeal Bill '“ raises the spectre of a clash between levels of government that may actually deserve the label. As a matter of law, the author is correct that the UK government can simply ignore the Scottish Parliament and National Assembly for Wales. But as the piece suggests, the political reality is that doing so would further weaken May's already enfeebled administration.
Is compromise possible? There is genuine annoyance in both Edinburgh and Cardiff at the way they believe the UK government has failed to engage with their proposals on Brexit in a serious manner. But it's about more than lack of engagement. Central government, on the one hand, and the devolved governments, on the other, seem to have fundamentally different understandings of what devolution means. It's hard to imagine how clever re-drafting of the bill alone can bridge the gap between them. With the bill set to be followed by further Brexit-related legislation that will whittle away at the powers of the devolved nations, we are entering a very difficult '“ and yes, crisis-ridden '“ period for the state's territorial constitution.
This article was originally featured on The Conversation