The Government has lost its High Court battle to trigger Article 50 and commence the process of leaving the European Union under its prerogative powers. What happened, why and what we can expect to happen next?

What happened? 

A group of campaigners went to the High Court to argue that the Government could not trigger Article 50 of the Treaty of European Union to commence the process of the UK leaving the European Union. Today, the High Court issued its judgment. The High Court said that as a matter of law, the Government could not trigger Article 50 without a reference to Parliament.

Why did the High Court say this? 

The question before High Court had to answer was whether the Government could exercise “prerogative powers” to trigger Article 50. In UK law, the Government (more formally, the Crown) has prerogative powers allowing it do certain things, like make international treaties, declare war or give honours.

However, the Government’s prerogative powers are limited. The Government cannot use its prerogative powers to change the law of the UK. This is a long-established principle of the UK constitution, dating back at least to 1610. The Government is subject to the law and cannot over-ride it. The importance of this cannot be overstated – a Government that can act outside the law is a tyranny. 

The court affirmed that the sovereign source of law in the UK is the “Crown in Parliament”. Law students know that Acts of Parliament are made by the Crown in Parliament – that is, with the consent of both Houses of Parliament and the Queen. The court uses the shorthand “Parliament” to mean “the Crown in Parliament”. This remained the case even when the European Communities Act 1972 came into force and gave European law primacy over UK law. (Primacy means that if UK law is inconsistent with European law, the European law is to be followed.) Parliament could pass a new law – a new Act of Parliament – saying that European law no longer has primacy. 

The Government argued that withdrawing from the European Treaties was a matter within its prerogative powers. Making and unmaking international treaties are prerogative powers.

However, the campaigners persuaded the court that if the Government exercised its prerogative power to trigger Article 50, then the result of this would be that the law of the UK would be changed. This is because 2 years after Article 50 is triggered, the European Treaties will stop applying to the UK, unless all the Member States of the European Union agree otherwise.

Most think it unlikely that all the Member States would agree to an extension. This would have a direct effect on the law of the UK because, under the European Communities Act 1972, European Law applies directly in the UK. So, by exercising its prerogative power, the Government would be changing laws created by Act of the sovereign Parliament by making European Law cease to apply directly in the UK. This is constitutionally unacceptable and unlawful. That is why the Government lost. 

Didn’t the law introducing the Referendum deal with this?

No. The Referendum Act 2015 (the “2015 Act”) merely said that there would be a referendum on whether to leave or remain the European Union and set out the procedures that would be followed to operate the referendum. However, the 2015 Act said nothing about the effect of the referendum result. The Government told parliament before the Act was introduced that the referendum result would be “advisory” only. The referendum result is not legally binding. As a matter of law, the referendum was merely the largest opinion poll ever carried out in the UK. It was and remains legally open to the Government to say that it will do nothing in response to the referendum result. However, the political ramifications of this may be extreme. 

What happens next? 

The Government has indicated that it will appeal to the Supreme Court. This appeal will take about a month. In the meantime, we are in limbo. If the Government wins the appeal, it will no doubt continue its stated strategy. What happens if the Government loses? The High Court has only told us what the Government cannot do: it cannot exercise its prerogative power to trigger article 50. However, by deduction, we can see that what the Government must do.

An Act of Parliament required 

The Government must ask Parliament not merely for a debate or a resolution, but for an Act of Parliament – a brand new law – giving the Government at the very least the power to trigger Article 50. The means both the Commons and the Lords will have to agree the to trigger Article 50. Politically, this blows matters wide open. 

Most parliamentarians were in favour of Remain – so this is a chance for Parliament to set, perhaps even re-set, the Brexit agenda. That said, the leader of the Labour party has already stated that Labour will not try to frustrate Brexit, but Mr Corbyn struggles to bring his party along with him on many policy issues.

The Conservatives are as fractious as they have ever been, so it is not clear that they will toe the Government line and the third biggest party, the SNP, considers it has a strong mandate from Scotland (which voted 62% to remain) to prevent Scotland leaving the EU at all. 

And there is the question of what that Act would say. Would it merely authorise the Government to trigger Article 50? Presumably it would have to go further and give the Government power to repeal the European Communities Act 1972 in its entirety at the end of the 2 year negotiating period. There is precedent for this in the Deregulation and Contracting Out Act 1994, which gave Government Ministers the power to amend Acts of Parliament in certain circumstances.

 But this creates a deadly impasse. Politically, Parliament will want some say or control over the extent of the Government’s discretion to negotiate Brexit, perhaps with some red lines (e.g., maintaining access to the Single Market). However, the Government will not want reveal its negotiating position ahead of commencing negotiations. The UK’s already weak negotiating position with Europe would be made markedly weaker.

But it seems politically difficult for the Government to ask Parliament for a wide ranging power to negotiate and implement whatever deal the Government comes back from Europe with. (“Trust us: we’ll get a good deal.”)

It is by the by, but this would be the inevitable result of the Government exercising its prerogative power to trigger Article 50. At the end of the two-year period, Parliament would either have to accept whatever deal the Government had managed to get, or the UK would simply leave the EU without a deal.

These are extremely difficult political questions, rather than legal ones. No party really has a mandate for negotiating Brexit, as “Brexit” was not defined before the referendum. In these circumstances, one would expect the Government would call an election to get a mandate for implementing Brexit. This would be extraordinary in itself, because official Labour and Conservative policy was to remain in the European Union.

Will Brexit happen? 

The pound rose markedly on the court’s judgment being issued – a sign that the money markets think that at least a “hard Brexit” is less likely. For all the difficult legal and political issues, it is very difficult to conceive of a situation where the democratic mandate of the referendum result is ignored.

Andrew Fleetwood is a partner at Gilson Gray