“This is the original version of the backstop that the EU offered, so it should be clear they are willing to still offer this,” says Prof Whelan.
That would leave Great Britain free to strike trade deals but Northern Ireland would not be part of them.
That would be anathema to the DUP and other MPs.
The second part of Prof Whelan’s plan is to use the Brexit political declaration to promise the citizens of Northern Ireland a referendum on the backstop, should it ever come into effect.
He suggests that five years after the beginning of the operation of a Northern Ireland-only backstop there would be a vote on whether to remain within the EU’s customs union and single market.
He says: “A promise to hold a referendum five years after the end of the transition period would provide a clear concession to those who believe the backstop arrangements would be harmful to Northern Ireland by offering them a chance to convince their fellow citizens to end the arrangements after a period.”
It proposes a new European customs association – a permanent customs union between the UK and the EU.
It would be superior to the customs deal Turkey has with the EU giving the UK “full and active participation”, instead of merely being a rule-taker.
However, it acknowledges even that would not be enough to keep the Irish border frictionless and the UK would have to effectively remain in the single market for goods and perhaps services.
In return for such an enormous u-turn by the UK, the institute says that the EU should also make a radical change on free movement.
The EU’s position is that the UK cannot enjoy full participation in the single market unless it accepts the four freedoms – one of which is the free movement of people.
The institute says the EU could “abandon its indivisibility dogma by which the four freedoms are inseparable, offering the UK to participate in product market integration but allowing it to make its own choices in other areas”.
It adds: “Most importantly, this concerns the mobility of people.”
Beef up the political declaration
The political declaration was published alongside the withdrawal deal and sets out the broad shape of the future relationship between the UK and EU.
EU leaders have said they are open to redrafting the declaration if the UK presents new ideas.