Referendums can often give a government an instruction that its ministers believe will be difficult to carry out. There is advice on how to handle this from a former Danish minister — here. [Shorter version: you can do what is in the country’s interests once you’ve exhausted every other acceptable possibility].
I don’t believe that any serious observer doesn’t at least suspect that Brexit will be a disaster for the UK and there may come a point where the downsides are so obvious and vast that the UK will try to throw the engine into reverse.
For this reason, it is hard to know how well Teresa May is doing her job at the moment. Her premiership has something of a Schrödinger’s Cat quality. Taking Mr Ørstrøm Møller’s advice, no matter what her ultimate intention is, the PM has no option but to pursue Brexit ruthlessly at this stage while quietly having an escape plan. For Remain voters, she is, simultaneously, the worst PM we’ve ever had while also being a saviour of Churchillian proportions.
The reverse is true for Leave voters (best PM or Quisling of almost … er…. Quisling proportions). Neither will know until the box is open.
One final point. If our liberal institutions are as withered as they appear to be, we could be in real trouble. If the UK’s negotiations are so incompetent that the country is faced with an outcome that is very clearly disastrous, and MPs still refuse to do their jobs as representatives, we may be in a situation where everyone outside the box can see that it’s been blown up, and the cat is dead.