Seven pro-EU MPs, MEPs and MSPs from four parties in Scotland are appealing to the European Court of Justice to rule whether Article 50 could be triggered without an agreement for Brussels.
It comes after the European Union’s chief negotiator Michel Barnier said earlier this week that any decision to reverse Brexit must be approved by the other 27 member states.
However, some experts believe the UK could choose to stay in the European Union without permission from Brussels.
And the Scottish MPs, MEPs and MSPs want to ask the case to Scotland’s high court to refer the issue for a ruling by the European Court of Justice (ECJ).
They claim the only way to be sure is for the ECJ to decide what “Article 50 means”.
In a statement, they added: “And because Article 50 must mean the same thing to everyone, a national court can’t give the answer.
“Only the specialist European Court in Luxembourg can interpret Article 50 definitively.
“So we will ask the Court of Session in Scotland to ‘refer’ it to Luxembourg. This is the only way to give our Parliament the best negotiating hand.
“To maximise its power if the right choice is to stick with what we have.”
The signatories include Christine Jardine, a Lib Dem MP and the SNP MP Joanna Cherry as well Scottish Labour MEPs David Martin and Catherine Stihler.
Scottish Green MSPs Andy Wightman and Ross Greer and the SNP MEP Alyn Smith have also signed their support.
Jolyon Maugham QC who is coordinating the legal action through his campaign group the Good Law Project told the Guardian that he thinks there is a legal case for the UK parliament to cancel Brexit.
The case also received a boost from the former head of the EU Council’s legal service, Jean-Claude Piris.
He wrote on his Twitter that Article 50 was based on the principle that withdrawing from the EU was a unilateral decision and nobody could force a state to leave.
The UK Government denied it had formally supported Mr Barnier’s stance that the Brexit process could be thwarted.
The UK Government’s Scottish law officer, the office of the advocate general, said: “For the avoidance of doubt, the public position we do recognise having taken is that the stated and consistent position of the government has been, and is, that the UK’s notification under article 50 (2) will not be withdrawn.
“This is clearly long established and consistent and discloses no basis for legal challenge.”
It comes after a legal action was started by Liberal Democrat parliamentary candidate Liz Webster.
She leads a crowdfunded group which claims Article 50 was never legitimately triggered, despite having been agreed by a vote in parliament, and says the revelation has the potential to halt Brexit.
The group has raised over £110,000 from ardent Remain supporters who hope the case could be their last-ditch way out of Brexit.
Their legal argument is that Article 50 requires a decision to withdraw from the EU to be made before it can be invoked.
Although 17.5 million Britons voted to leave, the plaintiffs in the Article 50 challenge say Gina Miller’s Supreme Court victory showed only parliament can decide to leave the EU.