It is reported that there are 342 MPs who will support a “softer Brexit” – including 255 Labour MPs, 25 Conservatives and 10 DUP – versus 297 supporting a “harder Brexit”. We seem to have moved on from the terms “soft Brexit” (staying in the European Economic Area, and thus retaining free movement, ECJ jurisdiction and EU financial contributions) versus “hard Brexit” (anything that isn’t “soft Brexit”) to the new terms “softer” and “harder”.

What could a “softer Brexit” mean, would 255 Labour MPs really support it, and would 255 Labour MPs, 25 Conservatives and 10 DUP really vote for it?

Let’s assume that a “softer Brexit” means retaining any combination of free movement, continuing ECJ jurisdiction and membership of the EU’s Customs Union. Could Labour MPs vote for that?

Labour’s 2017 General Election manifesto commits it to ending free movement with the EU. It states: “Freedom of movement will end when we leave the European Union…Labour will develop and implement fair immigration rules…New rules will be equally informed by negotiations with the EU and other partners, including the Commonwealth.”

Labour MPs hoping to hold Corbyn to his manifesto if and when he enters office will want to get into the habit of holding him to manifesto commitments. So retaining free movement simply isn’t going to be an option. (That also, incidentally, means that “softer Brexit” cannot mean “soft Brexit” in the old stay-in-the-EEA sense.)

Some folk might imagine Labour could skirt around the free movement issue by committing to stay in the EEA, thereby implicitly retaining free movement. They say there might be a Commons majority for that. But it would be easy enough for May to put forward a motion, before any EEA-retaining motion or negotiations took place, committing the UK government to ending free movement.

Labour MPs would have to vote for it.

OK. So no free movement. What about ongoing ECJ jurisdiction? Which bits of ongoing ECJ jurisdiction were we imagining Jeremy Corbyn would be in favour of? The rules forbidding state aid? The rules requiring liberalisation of and competition in the utilities and railways sectors? Much of Corbyn’s economic plan could not be implemented if we stayed under ECJ jurisdiction. So why would he whip his MPs to vote in favour of that?

No. All that Labour support for “softer Brexit” could mean would be staying in the EU’s customs union, without free movement or ECJ jurisdiction.

Given that’s all that “softer Brexit” could mean in terms of Labour votes, a series of questions arise. How many Conservatives truly aspire for us to remain in the Customs Union (and thus be unable to secure new trade deals outside the EU) with no ECJ or freedom of movement? Will the EU27 agree to the UK cherry-picking Customs Union membership without free movement or ECJ jurisdiction and the UK’s being free to use non-tariff barriers such as state aid (the halting of which is, after all, why the EU moved on to create the Single Market programme rather than stopping at the customs union stage it had reached in the 1970s)? Wouldn’t that set the EU back 40 years?

Turkey, of course, has a customs union with the EU without ECJ jurisdiction or free movement. So perhaps we should consider it conceivable. If the EU were to agree to the UK staying in the customs union without ECJ jurisdiction or free movement, what annual contribution would the UK be charged?

We should also ask: If Labour’s policy is to stay in the customs union only, without ECJ jurisdiction or free movement, what happens to services? Would there be a separate trade deal on that later? What of agriculture & fisheries? Would Labour want us to stay in the CAP and CFP?

A customs union with the EU in goods only is not a crazy idea, and it’s not completely inconceivable the EU could agree (with some appropriate undertakings on the future evolution of regulation and some way to resolve disputes). But it would mean the UK being unable to do its own trade deals internationally. And I think we must ask: Will 25 Conservative and 10 DUP MPs really vote with Labour, perhaps bring down the government ushering in the Corbyn era, for a Customs Union (plus CAP/CFP?) with no ECJ or free movement, continuing financial contributions, no deal on services & no scope to do deals with the US etc? When the government’s own policy is to seek a trade deal with the EU, with no ECJ or free movement, possibly continuing financial contributions, some kind of deal or transitional arrangement on financial services, with the main difference being that in the government’s policy the UK would be able to do our own trade deal with the US and under Labour’s policy we would not!

Do we really think 25 Conservative and 10 DUP MPs would risk precipitating another General Election and a Corbyn government for that?‎