Will Brexit Spark a Constitutional Crisis in the U.K.? Q&A

  • Brexit negotiator says new PM can trigger EU talks on her own
  • Some constitutional lawyers say Parliament must vote first

Brexit: Why It Might Not Happen

Britain’s shock referendum result has sparked a legal debate about who has the right to initiate the process of taking Britain out of the EU -- the Prime Minister or the U.K. Parliament? 

The debate cuts to the core of what Brexit will look like, raises legal questions that could dog the process for years and could play a role in deciding whether Brexit happens at all. If the matter isn’t resolved, it could lead to a constitutional crisis.

We try to untangle some of the arguments.

What legal standing does the referendum result have?

It is non-binding. The vote was an “advisory” referendum designed to recommend a particular course of action to the U.K. government. Such votes -- where an issue is put directly to the electorate -- are rare in the U.K. because of the guiding principle that sovereignty rests with Parliament. 

So just because the U.K. voted to leave the EU, it doesn’t necessarily mean it will happen.

Why does Parliament matter if the people have already spoken?

Some parliaments matter more than others, but Britain’s is a special case. It is the central pillar of Britain’s political system and, since 1689, has been “sovereign,” meaning that -- in theory -- it has the right to create or abolish any law.

Its supremacy, however, has been chipped away. The 1972 European Communities Act, which brought the U.K. into the EU, granted EU law primacy over many areas. 

There is also what’s known as the royal prerogative. Powers held by the Crown from medieval times have passed over time to the executive branch -- giving the prime minister the authority to act without the backing of Parliament in the conduct of foreign affairs.

Refresh your memory on why Britain is Quitting the EU, with this QuickTake

What does the Prime Minister say?

His lawyers and lieutenants have already said that invoking Article 50 of the Lisbon Treaty is up to the Prime Minister to decide. Triggering Article 50 starts a two-year countdown after which the U.K. would leave the EU.

Oliver Letwin, the minister overseeing the preparation for Brexit negotiations, told the foreign affairs committee in Parliament on July 5 that while there were “conflicting views,” government lawyers had advised him that “it is clearly” the prerogative of the prime minister rather than parliament to trigger the exit mechanism. 

He added, however, that this was “an entirely academic issue” because the involvement of Parliament would be needed down the line to repeal or “substantially amend” the European Communities Act, or ECA.

So is that it?

Not so fast, say Parliament’s defenders. Bringing in lawmakers to repeal or amend the ECA is like shutting the stable door after the horse has bolted because Article 50 would already have been triggered at that point.

Eminent jurists such as David Pannick and Geoffrey Robertson argue that the very fabric of U.K.’s constitutional monarchy is based on Parliament. On a matter this monumental, Parliament -- and not the prime minister -- should have the final say on when and whether Article 50 gets triggered. 

They cite the first paragraph of Article 50, which specifies that a country’s decision to leave must be made “in accordance with its own constitutional requirements.” So a premier acting alone would violate this basic tenet, they argue. 

Robertson was unequivocal: “It’s the right of MPs alone to make or break laws, and the peers to block them. So there’s no force whatsoever in the referendum result. It’s entirely for MPs to decide.”

If the government flies solo, it should expect this line of attack from Mishcon de Reya, one of London’s biggest law firms, which has been hired by a group of business clients to mount a legal offensive against Brexit. Lawyers are also grouping together to pressure the government, with more than 1,000 signing a letter urging the government to give lawmakers a free vote.

Does Parliament actually oppose Brexit?

Not right now. While almost three-quarters of lawmakers backed the Remain campaign, the leaders of all the main parties have pledged to respect the will of the people. Voting against the will of the people might not be the smartest thing for lawmakers who hope to get reelected one day.

So why do these differences matter?

The debate might look abstract, but the tensions between the Prime Minister and Parliament have the potential to blow up into a constitutional crisis

It’s true that everyone is promising to respect the will of the people right now. But what if voters change their minds? What if the U.K. falls into a deep recession? What if the next prime minister calls a snap election and there’s a swell in support for lawmakers arguing for a rethink of the referendum?

In that situation, the legal implications of who approves what and when could become very important and destabilizing for markets.

Can the Scottish Parliament block Brexit?

First Minister Nicola Sturgeon has said she’s examining this. 

One of the conventions that has emerged since Scotland got its own assembly in 1998 is that the U.K. Parliament won’t legislate on Scottish matters without the consent of the government in Edinburgh. This is known at the Sewel Convention.

As repealing EU law would also cancel huge swathes of the legislation that governs Scotland, the regional assembly could choose to withhold consent from a decision to trigger Article 50.

Of course, the Parliament in Westminster is sovereign and can ultimately choose to override Scottish objections. But politically, it would be a very risky path to take.

What’s the conclusion?

Britain doesn’t have a codified constitution, so there’s no clear answer. The politics will be complicated by the fact that the next prime minister heading the negotiations won’t have been elected directly by the people, unless Theresa May or Andrea Leadsom call snap elections.

If it ends up in the courts, a legal battle over triggering Article 50 could become the most important constitutional lawsuit ever decided, said Jeff King, a professor of law at University College London. 

"It’s quintessentially a legal question and ultimately for an authoritative ruling you can only look to the courts on that.”

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