They say that if you repeat the same lie often enough, you will start to believe it.

Ever since the prospect of a second Brexit referendum - affectionately called "the People's vote" - first found traction among pro-European Labour and Conservative MPs, UK Prime Minister Theresa May has categorically denied that this would ever be a viable option. But at the same time, she has also intimated during speeches that, if her deal with the EU is defeated in Parliament, it could mean "no Brexit at all". The motivation behind this inconsistency shouldn't be hard to spot: May needs a cudgel to browbeat defiant European Research Group MPs into supporting her plan - even as her government has chosen to withhold the attorney general's full legal interpretation of the draft deal, stoking suspicions that May is trying to cover up some of the less popular attributes of the deal, like the possibility that it could leave the UK permanently yoked to the EU customs union without the representation to help shape trade rules that it enjoys presently.

This hasn't stopped Wall Street banks from pricing in a relatively high likelihood of a second referendum (Deutsche Bank recently put the odds at 30%, while others have put it higher).

With opponents of her government threatening contempt or censure proceedings if she refuses to cave, May is swiftly running out of options to try and drum up support for her draft deal (though a handful of key cabinet ministers have come out in support of her "imperfect" deal).

Fortunately, on Tuesday, the purportedly "politically independent" European Court of Justice has just handed her a new tool that could come in handy during the debate over the deal as May works to whip up votes. To wit, the ECJ issued an advisory opinion on Tuesday that May would be allowed to legally reverse the triggering of Article 50 of the LIsbon Treaty - a decision that would effectively reverse the Brexit process.

While the opinion is "purely advisory", the Court typically follows this type of guidance in its rulings.

While the opinion is purely advisory, the Luxembourg-based court usually follows such advice. A date for a final rulings hasn’t been set yet but could still come this month, potentially even before the U.K. Parliament’s Dec. 11 vote on May’s Brexit deal.

To be sure, it's certainly possible that, if May had tried to reverse the invocation of Article 50 unilaterally, UK court would have backed her up. But by offering its advisory opinion, the ECJ is effectively handing May an 'out'. If the UK is careening toward a 'no deal' exit during the days before Brexit Day, May could rely on this opinion to justify threats that there will be - as she said the other week - "no Brexit at all" - if MPs don't vote for her deal.

Bloomberg hinted at this in its story about the ruling:

"The possibility continues to exist" to revoke the Brexit notice "until such time as the withdrawal agreement is formally concluded," Advocate General Manuel Campos Sanchez-Bordona of the EU Court of Justice said in a non-binding opinion on Tuesday. This opinion - fought hard by May’s government - could actually turn out to be a weapon she can use to her advantage as the country heads into uncharted Brexit territory. The possibility that the U.K. can go back on its decision will be alarming to Brexit hardliners, encouraging them to grudgingly support May’s much-maligned roadmap for how the country should quit the block.

Then again, BBG reasoned that using the ruling as a cudgel could backfire by encouraging pro-European lawmakers to push for the cancellation of Brexit.

Still, a decision saying that Article 50 can be unilaterally revoked favors those who want to remain in the EU and could help those campaigning to thwart Brexit with a second referendum. It could also encourage some wavering pro-EU lawmakers to vote against May’s deal. It would put "the decision about our future back into the hands of our own elected representatives - where it belongs," pro-Remain lawyer Jolyon Maugham, who brought the lawsuit, said on Twitter. "On this critical issue, I’m sure MPs will now search their consciences and act in the best interests of our country."

Former UKIP leader Nigel Farage argued that the recommendation is just the latest sign that "every effort" to stop Brexit is being made on both sides of the channel.

ECJ says the UK can revoke Article 50 without permission. Every effort is being made on both sides of the Channel to stop Brexit. — Nigel Farage (@Nigel_Farage) December 4, 2018

After the ruling, a spokesman for May's government reiterated that "it remains a matter of firm Government policy that Article 50 will not be revoked."

And while that may be true for now, if May's draft deal doesn't pass during next week's vote, forcing both sides to step up preparations for a 'no deal' Brexit, the political calculus could swiftly change.