Plea to contribute.
I don't normally contribute to this kind of stuff but I did here. This is in my view the most important legal initiative after the Gina Miller case. It seeks clarity from the ECJ about the single sided revocability of A50 by Parliament. It is run by Jo Maugham QC via the Good Law Project.
There already is a legal opinion - called the Three Knights Opinion - which covers the gist of the case, but such is never as good as the ECJ being the only court with jurisdiction in the matter.
Core Conclusion
Therefore, if Parliament were to refuse to give legal effect to the terms of a withdrawal agreement negotiated with the European Union, or were to refuse to authorise withdrawal in the absence of any agreement, the notification given by the United Kingdom of its intention to leave the European Union could be treated as having lapsed (since the constitutional requirements required to give effect to that intention had not been met), or could be unilaterally withdrawn. Article 50 cannot have the effect of ejecting a Member State from the European Union contrary to its own constitutional requirements.
I'm sure this will easily reach £50k. I'm posting in case you feel you want to contribute to a useful anti-Brexit cause.
A50 PROJECT