I don't think so as there is no provision for this in A.50. So there is no legal right to unilaterally withdraw, but the Council, as a political body, can make a political decision to accept a withdrawal. But it is not legally obliged to accept such a withdrawal, and it may require unanimity for it to do so.

I agree that popular opinions haven't (yet) shifted enough to make a different referendum result inevitable, although small majorities for remain are evident in the polls. In my scenario above I am banking on the continuing negotiating debacle that is the Tory government to sufficiently disillusion leavers, combined with the only alternative being a potentially disastrous "no deal" Brexit.

On the EU27 side I don't see there being a lot of scope for ongoing recriminations about the Brexit deal because it won't effect most members all that much - Ireland and perhaps Holland/Belgium being the exceptions. The Canada or other FTA's tend not to be the subject of ongoing popular recriminations afterwards.

Obviously if citizens are effected directly, e.g. by having to have a visa to travel to or work in the UK, there will be complaints. It's hard to see how they would blame the EU for that however, as controlling migration is explicitly what Brexit was mostly about. A hard border in Ireland would however poison domestic politics indefinitely...

Index of Frank's Diaries