Forget Brexit's Article 50 - why you need to know about Article 127

Following the court battle over the Brexit-triggering Article 50 that ended with MPs voting unanimously to pass the bill, there is now a new legal fight which could delay Britain's exit from the EU - and it's all about Article 127.

Here we explain what the High Court case is all about.

  • Who is challenging the Government?

Think tank British Influence is launching the legal challenge, warning the Government could act unlawfully if it assumes that leaving the EU means Britain automatically departs the single market too.

They are seeking a formal judicial review of the Government's position - a legal action that could end up in the European Court of Justice.

  • What is British Influence's claim?

The think tank believes Britain will need to take separate measures to leave the European Economic Area (EEA) after Brexit, arguing it is separate to EU membership.

The single market, which offers tariff-free movement of goods, services, money and people, is dominated by but not exclusive to EU members.

It also includes non-EU members like Iceland, Lichtenstein and Norway.

  • So what is Article 127?

Article 127 is the exit mechanism of the EEA agreement.

According to British Influence it is this measure alone that can formally end Britain's participation in the single market.

They also want Parliament to ultimately decide whether to trigger Article 127, though the think tank will argue for staying in the single market.

  • Why could it delay Brexit?

Another lengthy legal battle for the Government to clarify its position on exiting the EEA could push it back plans to begin the formal process of leaving the EU.

However, British Influence insists it is not pursuing delay tactics.

  • What is the Government's response?

The think tank will outline its position in a letter to Brexit Secretary David Davis. Credit: PA

The Government rejects the think tank's central claim, insisting EEA membership ends when the UK leaves the EU.

The Government added it was particularly reluctant to discuss anything that could "undermine" forthcoming Brexit negotiations.

A spokesperson said: "The future relationship between the UK and the EU will be subject to negotiations. It's not in the UK's interest to give a running commentary on our thinking that could undermine our negotiating position."