By treaty, there are no negotiations and not even talks about what comes after or the details of exit until after the process is officially initiated under article 50 of the Lisbon Treaty.
And once begun the exit process must be completed in 2 years.
If no satisfactory agreements are reached by then that's just too bad, the state that has asked out is then just out, ready or not, happy or not.
And there are no provisions for stopping the process or a change of mind once article 50 is invoked.
So this is just more Brit self-delusion and fantasy politics, whatever huffing and puffing the politicians and pettifogging lawyers may indulge.
Owen Smith to offer referendum on Brexit deal if elected Labour leader
Owen Smith has set out his stall for the Labour leadership by saying he would offer the public a second referendum to ratify any Brexit deal Britain strikes with the EU.
In an interview with the Guardian, the Pontypridd MP accused Jeremy Corbyn, the Labour leader, of acting selfishly and warned that his party was “teetering on the brink of being destroyed”.
Smith, whose entry into the race for party leader threatens to derail the hopes of Angela Eagle, who first triggered the contest, said it was clear people wanted both access to the single market and controls on immigration.
But, he added, the public wanted to know what deal would be struck, adding:
“And then we should give them another chance. That does mean a second referendum or a general election when the terms are clear. The Labour government should be committing to that.”
The mechanics of leaving
On the other hand, once a member state of the EU exits under Article 50 it can seek to get back in under Article 49, the normal procedure according to which states may seek to join.
No shortcuts are provided in the Lisbon Treaty for states that were members but dropped out getting back in.
The leading member states of the EU have to date shown no sympathy at all for Brit politicians trying to invent for themselves a process by which they can test the waters by dipping in their toes, and then slowly wade in, and turn around and come back out if they want.
The officially specified and treaty-governed process calls for a quick jump off the diving board into the deep end of the pool.
That's all there is.
It's a pig in a poke when Article 50 is invoked and, once invoked, there is no stopping the exit.
There is only re-application for admission.