Three Green Party politicians have put their name to a legal challenge on whether Brexit is permanent.
Papers are being lodged in the High Court in Dublin today as lawyers take their case to Ireland in a bid to seek a ruling on the issue from the European Court of Justice.
The aim is to find out if Article 50 can be revoked if the UK ever decides to rejoin the EU. It will argue that Britain was excluded from European Council Brexit meetings, that Ireland attended.
Jolyon Maugham QC, director of the UK-based Good Law Project, is taking the challenge along with Jonathan Bartley, co-leader of the Green Party of England and Wales, outgoing Stormont Green MLA Steven Agnew and Keith Taylor, Green MEP for South-East England.
They hope the case will be heard in March or April, around the time that British Prime Minister Theresa May is planning to trigger Article 50 to take Britain out of the European Union.
Mr Maugham said he respects the referendum outcome but has concerns over the future.
"No one knows what lies around the corner. And it's in our interests that we have the option of remaining if new evidence shows that leaving is damaging people's job security or rights at work or our ability to fund the NHS or national security," he said.
Mr Maugham said that establishing that the Article 50 notification can be revoked gives us a free option in an uncertain world.
He added: "Whether to exercise that option is for the electorate. But no one can deny that our national interest is served by us having it."
The case is being paid for with £70,000 from crowd-funding including almost 1,300 donations of £25 or less and more than 1,700 donations of £50 or less.
It will argue that Britain was excluded from European Council meetings related to Brexit and the case is being taken in Dublin as Ireland took part in those discussions.
It will also seek an opinion from the European Court of Justice on whether Article 50 can be reversed by the UK Government without consent from the European Union member countries.
Mr Bartley said: "This is about putting power in Britain's hands. We're asking the courts to give everyone clarity on the legal question of whether, in the event of things going badly wrong, or the country being driven over a cliff edge, the Government would be able to revoke Article 50."
Mr Agnew said: "The unique status of Northern Ireland is being ignored with our traditional parties involved in local squabbles.
"Any deal on the Irish border will have massive implications across the island and it is vital that the people of Northern Ireland have a say on the final proposal."