The final stages of the EU withdrawal bill are when events happen so rapidly realities can change in an instant
Should remainers now “get behind” Brexit and turn their energies to shaping a close UK-EU relationship or to rejoining the EU post-Brexit? That is what some anti-Brexit campaigners (paywall) and respected Brexit commentators have started to accept. The essence of their point is that all the legal routes to stopping Brexit are now politically too unlikely and that, since the mandate from the referendum was only to leave the EU, all that happens afterwards is up for grabs.
But for remainers to give up on the campaign to stop Brexit would be wrong on principle, and practically ineffective.