Brexit: Landmark High Court Ruling that Parliamentary Approval is Required to Trigger Article 50

Posted on 11th January, 2016
, in UK 

Estimated reading time 6 minutes

The Summary

Claimants, including a group known as "The People's Challenge to Article 50", have succeeded in obtaining a declaration from the High Court that the Government does not have the legal power to notify its intention to leave the EU under Article 50 of the EU Treaty of Lisbon, without the prior authorisation of the UK Parliament. This is a victory against the Government’s position that it could trigger Article 50 for the UK to withdraw from the EU through the use of Crown Prerogative. Not only is the judgement itself historic but also it is a testament to the influence that crowd funding can have on major issues of the day.

The UK Government immediately notified its intention to appeal and the Court has permitted the appeal to leapfrog directly to the Supreme Court and be heard on 7 and 8 December 2016. Unusually – and perhaps reflecting the perceived importance of the case – it will be heard by all 11 Supreme Court Judges. The “People's Challenge" have now launched a second crowdfunding campaign on platform CrowdJustice to fund the defence of the High Court ruling in the Supreme Court. The campaign, which launched shortly after the verdict was given, has already hit its target of £75,000 in less than 24 hours and that figure is increasing.

The Facts and Arguments

Article 50 sets out the procedure for the withdrawal of a Member State from the EUThe procedure must be in accordance with the state’s own constitutional requirements. Once triggered a two year time period starts for negotiating the terms of the exit (this time frame can be extended on a unanimous vote).

Prerogative powers enable the executive branch of the Government to act on behalf of the Crown in relation to foreign matters including the entry and secession of international treaties. The Government had intended to rely on Crown Prerogative to trigger Article 50 and implement the outcome of the June Referendum. 

The Claimants argued that triggering Article 50 without Parliamentary authorisation is contrary to the UK constitution as it would frustrate the rights and duties arising upon membership of the EU. Such rights have been enshrined into the UK domestic law by the European Communities Act 1972 (ECA) and it is not a matter available to the Government under Crown Prerogative.

The Judgement

The Court upheld the Claimants’ arguments. The Court held that giving notice under Article 50 would have the effect of changing domestic law as legislated by Parliament under the ECA.  It is a strong constitutional principle that Crown Prerogative cannot be used to vary domestic law and individual rights conferred by legislation and enacted by Parliament. Any repeal of legislation must be made by Parliament itself and giving notice under Article 50 would inevitably mean the repeal of the ECA.  The fact that Parliament would have an opportunity to vote on any subsequent negotiated treaties for withdrawal from the EU is not sufficient to satisfy these constitutional requirements.

It was agreed by both sides that notice under Article 50 could not be given conditionally and, once invoked, it would inevitably lead to the UK withdrawing from the EU.  It was also agreed that to do so would result in profound changes to domestic law.

The Court also noted that the referendum had advisory effect only and did not provide any legally binding mandate to the Government to claim that it had a right to trigger Article 50 without first having the support of Parliament.

Our Thinking

If the Supreme Court does not uphold the Government’s appeal, the matter will need to be put before Parliament in the form of primary legislation.  The extent to which the Government might feel able to put forward their detailed negotiating objectives for withdrawal remains uncertain. To date the Government   has taken the position that to reveal those objectives would weaken its negotiating stance but MPs are likely to want some indication of its intentions if their support is to be given.  The Government has a small majority in the House of Commons (though not the House of Lords) and, while MPs generally are unlikely to vote in a way which frustrates the vote in the EU referendum, there are some who may require a clear indication, for example, as to whether the aim is to remain in the Single Market.

The Government has previously indicated that it intended to trigger Article 50 by the end of March 2017. If the Supreme Court upholds the decision this may now prove to be too optimistic as to go through the normal procedure of both the House of Commons and the House of Lords as well as committee stages by March 2017 may present some logistical problems, particularly with such a sensitive and controversial underlying issue.

We will report further as the case progresses.

We are here to help

Abbiss Cadres has a unique service model incorporating all the expertise needed to help you manage the complexities of your clients’ employment issues.  As well as employment law, our services include mediation, immigration, tax, pensions, compensation and benefits and global mobility (including compliance services).  We have extensive experience of working alongside a variety of corporate legal teams where we are seen as either an additional resource or as an expansion to their current HR-facing services.  Either way, we offer seamless support to help you help your clients.

For more information on how we can help you with this or another employment related issue get in touch with us on 0203 051 5711 or email


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