You can't stop it. Even if Brexit was reversed - which I doubt even possible - Britain has been shown to be a source of political risk. That isn't going away.
the question isn't if the EU still wants the UK (but that it's unlikely that in the current local political internal climate and the opposition it isn't likely. Though certainly legally possible.
the danger to the UK automotive sector: https://www.youtube.com/watch?v=Pq2Z9uHzsGM
edge cases such as aviation (not a fan of Ryan air CEO but still worth watching): https://www.youtube.com/watch?v=Inr1KEoJqJ0
and here a longer one about the effects of Brexit - it is worth every minute IMO: https://www.youtube.com/watch?v=EcIkIz98zXU&
It's very tricky because Brexiteers/Remainers cut across both Labour and the Tories and yet the party members are expected to toe the party line. Which results in an impasse.
The complete agreement of every EU nation is required to un-invoke article 50, because there are no provisions for it. Now, they'd likely do it, but that isn't a certainty, especially as the UK arguably gets a lot more out of the EU than most other member states relative to investment.