It might be barely seven years old, but the supreme court has weighed heavily on the constitutional scales to correct a perceived imbalance in the relationship between parliament, government and voters.
“To proceed otherwise would be a breach of settled constitutional principles stretching back many centuries,” intoned Lord Neuberger on Tuesday as he reasserted the right of MPs to be consulted on whether Britain should begin the process of something as far-reaching as leaving the EU.
Yet within minutes of the court judgment, parliament indicated it was not at all sure it was ready to assume such power – especially if it means facing down the result of the June referendum or a media consensus that only the directly expressed will of the people should be sovereign.
“Labour respects the result of the referendum and the will of the British people and will not frustrate the process for invoking article 50,” said Jeremy Corbyn in a statement that swiftly closed off any meaningful likelihood of enough MPs opposing the government’s imminent Brexit bill.
Though the government hopes a short vote on an even shorter piece of enabling legislation will now therefore be enough to proceed as before, there are growing signs that this is only the start of parliament’s newfound responsibilities.
The first battle will come over amendments to the bill. Anything deemed overly obstructive is unlikely to attract a majority, but there are plenty of procedural tweaks that could still have profound implications for how, when and even whether Britain leaves the European Union.
In theory, the supreme court was silent on this issue. “The issues in this proceedings have nothing to do with whether we should exit the EU, or the terms or the timetable,” said Neuberger.
In practice, the door is now open for parliament to continue to have a meaningful role throughout the process – should it choose to do so.
The government has already conceded that MPs should have a vote on whatever deal it manages to secure with the EU at the end of the two-year article 50 process.
Theresa May would like this vote to be a largely symbolic rubber stamp. If MPs do not approve of her deal, the alternative, according to the government, is that Brexit proceeds in a disorderly manner instead, with Britain crashing out of the EU unilaterally and relying on World Trade Organisation tariffs to replace the single market.
Yet there is also a separate legal challenge in the Irish courts which could lead to the European court of justice ruling that article 50 is not a one-way door.
In this scenario, a rebellion by MPs over the terms of a unattractive exit deal could lead to them demanding that the whole question of Brexit be put back to the British people – either in another referendum or, more likely, a general election, perhaps as soon as the spring of 2019.
Little of this was immediately apparent in the political reaction to Tuesday’s supreme court decision. “The British people voted to leave the EU and the government will deliver on their verdict, triggering article 50, as planned, by the end of March,” said a Downing Street statement. “Today’s ruling does nothing to change that.”
Yet much has changed since the referendum and when the courts first took up the question of whether parliament needed to approve Britain’s departure.
As the prime minister acknowledged in her speech last week, Brexit is now certain to mean leaving the single market and customs union in ways that many leave campaigners denied during the referendum campaign.
Even May’s promised concessions on continued market access and an unspecified hybrid customs union are seen as highly unlikely by most European politicians. It may therefore prove increasingly hard for MPs to hide behind the argument that the people have spoken and nothing has changed.
Whether parliament wants to grasp the nettle or not, the supreme court has set up two years of potentially fierce debate over what happens not just at the start of the Brexit process but, perhaps more importantly, also at the end.