A legal challenge is being launched in the High Court to determine whether Brexit is permanent.

Papers will be brought by the UK-based Good Law Project, supported by members of the Green Party.

The aim is to find out if Article 50 - the mechanism for leaving the European Union - can be revoked if the UK ever decides to rejoin the EU.

It is hoped the case will be heard in March or April, around the time British Prime Minister Theresa May is planning to trigger the leaving process.

It will argue that Britain was excluded from European Council meetings related to Brexit.

Dublin is the venue of choice because the Irish Government took part in those discussions.

The European Court of Justice will be asked for opinion on whether Article 50 can be reversed by the UK without consent from EU member countries.

Those taking the action say it is for the people to vote on weather they want to re-join, but it is important the option is there.