Emily Jones and Calum Miller explain why – contrary to Boris Johnson’s belief – Britain can not have its cake and eat it too. They explain the three “incompatible” goals that the government and parliament seek to achieve: preserving the country’s territorial integrity, preventing the return of a hard border between Northern Ireland and the Republic of Ireland, and enabling the UK to strike its own trade deals. In essence, they have created a trilemma they refuse to acknowledge.

Realistically speaking, “only two of these objectives can be met at any one time.” Cherry-picking the right options has proved very “intractable.” The authors see “three basic scenarios” for moving ahead. However they all involve “tradeoffs” and there is little appetite for compromise. As the chaos drags on, Britain needs a leader to take the country out of the “current impasse.” Most of all it needs “urgently” a national debate to “rank the electorate’s preferences.”

The first scenario is called a “free-trade union,” which would allow Britain to have autonomy over its own trade policy and territorial integrity in exchange for the return of customs and regulatory checks at the border between Northern Ireland and the Republic of Ireland. The UK would leave both the EU customs union and the single market. This is a “hard” Brexit that Tory hardliners want.

The second scenario would address the Irish question. The UK could have its trade policy autonomy without a hard border in Ireland by sacrificing territorial integrity. Northern Ireland would remain in the EU customs union and single market while a border would be set up in the Irish Sea between the UK and NI.

But the authors point out that different parts of the UK would have different trade rules and regulations. Unionists in NI would object to being separated from the rest of the UK, raising the risk of renewed conflict. And Scotland would probably demand its own closer relationship with the EU. Another Scottish independence referendum would lead to the breakup of the entire UK.

The third scenario would allow the UK to avoid the Irish question and preserve its territorial integrity. But it would have to abandon the vision of “Global Britain” by remaining in both the customs union and single market. And there would be no meaningful autonomy over trade policy – an essence of the “Common Market 2.0” proposed by a group of Labour and Conservative MPs.

Referred to “Norway Plus”, the MPs see “Common Market 2.0” as an alternative model for the UK's future relationship with the EU after Brexit. This would take the UK back to an economic relationship it had with the European Economic Community in the 1970s and 80s, without being tied to a closer political union or a direct involvement of the European Court of Justice. But it would have to allow migration from the EU, making contributions to the EU budget and following EU regulations etc.

The authors say even a simple customs union with the EU – which has come closest to winning a parliamentary majority – won’t solve the Brexit trilemma. In case the UK could regain control over immigration, it would require new regulatory checks between Britain and the EU. Worse, Britain would be locked out of the single market in services, which constituted around 40% of British exports to the EU in 2017.

The reason why MPs rejected Theresa May’s withdrawal agreement three times is that, it leaves open the details of the UK’s future relations with the EU, but it does include the backstop to prevent the return of a hard border in Ireland. Although she rules out a “hard” Brexit, she also leaves the inevitable choice between trade-policy autonomy and territorial integrity for the next stage of the Brexit negotiations. Tory hardliners are determined to put trade policy autonomy before the Good Friday Agreement, which means they would accept a border through the Irish Sea.

The authors say the government and the parliament can choose between one of the three Brexit scenarios and suspending the Brexit process altogether. Due to the lack of “a mature and frank discussion, the UK will continue to bear the costs of interminable uncertainty and indecisiveness.”

If politicians can not agree, they should let voters decide, who would have to be pragmatic and “move past transactional, tribal politics and embrace leaders who are willing to reach out to the other side and speak honestly about policy tradeoffs.” Only a national discourse would heal the wounds and bring the country together, reaching consensus that all can respect and live with.