Michel Barnier made this pronouncement in 2016, which is certainly coming true:
"I would have succeeded in my task if, in the end, the deal is so hard on the British that they’ll prefer staying in the EU.”
Here is the original French:
The EU has every incentive to make life as hard as possible on the Brits if they actually leave as planned. Any real compromise is virtually impossible under EU rules that require the unanimous consent of all remaining member states. In addition, real compromise would increase the risk that other countries would follow the UK’s example and the EU would disintegrate. The fact that the EU may suffer as a result of a no-deal Brexit is not a major consideration in this equation.
As far as popular unrest in the EU, there is no practical way to change the basic structure of the union. The only real option is something like, "beatings will continue until moral improves . . . "