The United Kingdom is staring down the barrel of the Brexit gun. Virtually all economic projections — including those leaked from the Treasury — suggest that any version of Brexit will make the United Kingdom worse off than remaining in the European Union.

And there is the issue of what to do about Ireland. The “phase 1” agreement says that if the United Kingdom does not come up with a solution to keeping an open Irish border, then it will align with EU law, while having no say in its content — all at the cost of many billions of euros. The United Kingdom agreed to this in principle, but when it was reduced to a draft legal text, Prime Minister Theresa May said, “No UK prime minister could ever agree to it.”

Many are asking why she had not thought through what she might realistically sign before giving notice of the United Kingdom’s intention to leave the European Union. But, by her letter of March 29, 2017, the prime minister exercised her power under article 50 of the Treaty on European Union to give notice of the United Kingdom’s intention to leave the European Union. Some, including apparently her own government, believe that the inevitable consequence of this letter is that by midnight on March 28, 2019, unless the negotiation period is extended by agreement with all other member states, the United Kingdom will have to leave whether or not any deal has been done. In effect, if there is no deal, the United Kingdom will fall out of the European Union in the hardest of “hard” Brexits.

Is this right? If no deal can be negotiated that is acceptable both to the European Union and to the UK Parliament, is leaving without a deal the only option? In my view, it is important to appreciate the range of available options. And, in my view, the question is not “deal or no deal.”

As a matter of law, the question is not only how to depart, but whether the United Kingdom is bound to do so at all. The possibility of remaining a member of the European Union is barely being spoken about in the political forum at present: there is no perceived political will to remain in the Union. But as people start to understand the full implications of Brexit, perhaps after the “meaningful” parliamentary vote on the terms of any available deal, it is entirely possible that the public mood — and with it, the will of Parliament — could change.  

And the will of Parliament does still matter. Many lawyers believe that Parliament could instruct the prime minister to withdraw the United Kingdom’s notification of its intention to leave, and that (if it did so), the United Kingdom would not be bound by the terms of article 50 of the Treaty on European Union to leave anyway, on the basis of the March notice letter.

As a result, it matters that future political conversations about what the United Kingdom should do are properly grounded in a constitutional understanding of what it could do, if Parliament changed its mind. A week may be a long time in politics, but 350 years is quite a short time in British constitutional law.

After the Brexit referendum on June 23, 2016, a number of people, including Gina Miller, a British business woman, challenged the UK government’s assertion that it could trigger Brexit on the basis of the referendum result alone, without further parliamentary authority. Before the hearing, this legal argument  was dismissed as “remoaner” time wasting by those who had voted “remain” in the referendum. The government said that Miller would definitely lose. But she won. 

The Divisional Court gave its judgment on November 3, 2016, and pointed out that the language of the EU Referendum Act 2015 had done no more than allow the government to hold an advisory referendum. It did not say what would happen after it took place. The court relied on the Bill of Rights to hold that the government needs parliamentary authority to change the law. It was Parliament that brought the United Kingdom into the European Union by passing the European Communities Act 1972 and made EU law part of UK law. As a result, only Parliament has the authority to stop EU law from applying directly in the United Kingdom.

That seemed to most lawyers like an obvious restatement of what one academic called “Constitutional Law 101.” Surprisingly, the UK government appealed. After a televised hearing — which briefly made a bunch of fusty constitutional lawyers into unlikely reality TV stars — the Supreme Court agreed with the Divisional Court.

The government lost no time in introducing the European Union (Notification of Withdrawal) Bill 2017 on January 26, 2017, just two days after the Supreme Court judgment. It received royal assent and became an act of parliament less than one month later, on February 16. And the prime minister formally notified the European Council of the United Kingdom’s intention to withdraw from the European Union on March 29. 

But — as a similar bunch of fusty constitutional lawyers pointed out at the time — that act should have been called the EU Notification of Intention to Withdraw Act. Contrary to the transport secretary’s understanding, Parliament did not vote to leave the European Union. The bill that the government introduced so hastily only gave the prime minister power to give notice of her current intention to withdraw the United Kingdom from the European Union, but not to actually leave. 

Again, the government was warned: a Labour amendment was put forward with cross-bench support that would have given the prime minister statutory power to withdraw the United Kingdom on the basis of a mere parliamentary resolution. But the government whips instructed members of the House of Lords to vote against it, and it was defeated.

In vain, expert cross-bench peers, including Lord Pannick (who argued the Miller case) and Lord Kerr (who drafted article 50) lined up to point out to the government that in the absence of this amendment, the prime minister would not have the authority to take the United Kingdom out of the Union. The government refused to amend the bill to reflect this constitutional reality, and the act passed without any provision as to how and when Parliament would give permission for the Brexit deal (or no deal) to actually take place.

As Lord Hope, the former vice-president of the Supreme Court, put it in the House of Lords debates, “I...caution the Government against thinking that this Bill on its own will give them all the authority they need, or that obtaining approval for an agreement by resolution is the same thing as being given statutory authority to conclude that agreement.

“They could have provided for that in this bill…but it has not done so...they cannot escape from the effect of the Miller decision when we reach the end of the negotiation.”

Britain’s constitutional arrangements require parliamentary authority to leave the European Union, which has not yet been conferred. Indeed, the European Union (Withdrawal) Bill, which is the legislation currently going through Parliament (at the time of writing) to implement the terms of withdrawal, has been amended (after an unlikely rebellion led by Dominic Grieve, a former Conservative attorney-general) to ensure that Parliament does have a vote on the final deal with the European Union before it is signed.

But what happens if, as a result of that vote, Parliament rejects whatever deal is on offer?   The UK government says the only other option is to leave with no deal, but that is simply constitutionally wrong. In the absence of parliamentary authority, the prime minister cannot take the United Kingdom out of the European Union on any terms at all. And if the prime minister does attempt such a process, another successful court challenge is likely.

Again, Lord Hope said it best: “It is all about respecting the sovereignty of Parliament. The law will see to that whatever the Government think, as it always does.”

Thematics
The opinions expressed in this article/multimedia are those of the author(s) and do not necessarily reflect the views of CIGI or its Board of Directors.
  • Helen Mountfield

    Helen Mountfield, Q.C., is a barrister in England, where she is a founder member of Matrix Chambers, which has a strong international presence. She specializes in constitutional and administrative law, and has appeared in many leading cases in the Supreme Court, the Court of Justice of the European Union and the European Court of Human Rights. 

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