In May, the House of Lords select committee on the European Union published a detailed document on the process of withdrawing from the EU.
Among other things, the committee concluded that:
…we have no reason to believe that the requirement for legislative consent for its repeal would not apply to all the devolved nations.
-That is, Scotland, Wales and Northern Ireland.
The committee also concluded that, once Article 50 of Lisbon Treaty has been invoked, it can be reversed before the end of the two year negotiating period:
There is nothing in Article 50 formally to prevent a Member State from reversing its decision to withdraw in the course of the withdrawal negotiations. The political consequences of such a change of mind would, though, be substantial.
This is interesting in that it introduces yet another set of permutations to the many Brexit options. For example, Article 50 could be invoked by the UK, and then when the negotiations with the EU have reached, say, month 15, and it is clear what sort of deal the UK may get regarding exiting the EU, a general election could be held. If that general election results in a change of government, and the new government is elected on a mandate of rejoining the EU, then Article 50 could be reversed.
As they say on social media:
It is not fanciful to imagine the scenario where the United Kingdom, including its devolved nations, works through the various Brexit options and then reaches a “deal” with the EU which leaves us with three options:
1. Leave the EU, stay in the single market but have no say over the rules we have to abide by, keep paying nearly as much to the EU as we are now and have an emergency brake on immigration. Face a pitch-fork revolution from outraged “Leavers”.
2. Go onto “World Trade rules”, lose the City “passporting rights”, lose Scotland from the UK, unravel the Good Friday agreement in Northern Ireland by re-erecting a land border, but have full control over anyone who is daft enough to want to come into a country which has been reduced to economic and constitutional carnage.
3. Stay in the EU, save the economy, save the United Kingdom from breaking up.
Upon sober, collective national reflection, it may seem that simply staying in the EU is the most sensible option.