'Very likely post-Brexit EU agreement would need Parliamentary ratification'

Any new treaty agreement with the European Union following Brexit would "very likely" have to be ratified by Parliament, the High Court has heard.

A Government QC said the "view at the moment" was that ratification was likely if the royal prerogative was used to launch the Brexit process.

James Eadie QC was defending Theresa May's decision to rely on historic prerogative powers to trigger Article 50 of the Lisbon Treaty to leave the EU - without the prior authorisation of Parliament.

The Prime Minister's decision is under attack in a historic legal challenge launched by a group of campaigners, referred to as "concerned citizens".

They are asking the Lord Chief Justice, Lord Thomas, sitting with two other senior judges in London, to rule that Mrs May has gone wrong in law and is in danger of undermining the sovereignty of Parliament.

They say UK citizens face being deprived of statutory rights granted under the European Communities Act 1972, which made EU law part of UK law, without proper scrutiny by Parliament.

Mr Eadie told the court there still would be scrutiny. He argued that a minister using the royal prerogative to trigger Article 50 without prior parliamentary approval would only be "firing the starting gun" for the Brexit process, and it would not of itself change any common law or statutory right enjoyed by citizens.

Mr Eadie said: "Any such changes are a matter for future negotiations, Parliamentary scrutiny, and implementation by legislation."

Mr Eadie said that scrutiny was likely to include Parliament having to ratify any new treaty reached with the EU during the Article 50 process.

The QC said: "The Government view at the moment it that it is very likely that any such agreement would be subject to ratification."

But Mr Eadie stressed he could not go further than "likely" and say it was a certainty.