EU referendum, brexit and the aftermath

The red-lines that Corbyn and McDonnell have set means option 3 or 4, if they win in June:

There are four options:

1. Revoke Article 50 & Remain
   
2. “Norway” - minimal economic impact, democratically outrageous
   
3. “Canada” - FTA - major economic hit
   
4. “WTO” ie cliff edge - catastrophic
   
   

But on the other hand, with a Labour government I think 4 is much less likely than with the Kremlins favourite, JRM.