It is impossible not to be both cynical and angry about the government’s “future partnership paper” on customs arrangements with the EU, which was published on Tuesday. Like the other papers on Brexit themes that are expected from Whitehall in the coming days, this one seems less concerned with its ostensible purpose, UK policy towards the EU after Brexit, than it is with the management of internal Conservative party divisions. The document is primarily an attempt to signal to MPs that Theresa May’s government is back at its desks and back in business after its election debacle, and is now working together as one. It is not a serious attempt to set out a desirable relationship with the EU that stands up for Britain, its economy, its workforce and this country’s values.

The document is being spun as a contribution towards the soon to be resumed Brexit negotiations between the UK and the EU. But that is largely pretence. Those discussions, which aim to reach some agreements in October, are not about future customs arrangements. They are strictly focused on the rights of EU and UK citizens in one another’s jurisdictions after Brexit, on the Irish land border and on the financial settlement between the UK and the EU. Even if the new document were remarkably interesting and enlightened – and it is neither – the issues with which it deals are for later in the process, as critics were quick to point out.

Most of what it contains, and most of what the Brexit secretary, David Davis, said about it on Tuesday, is little more than flannel. The paper speculates about ways in which future customs arrangements could be made simple and frictionless – as they are at the moment. But the words are aspirational not concrete. Alternative approaches are rehearsed, yet the government does not say which of them it prefers. Terms like “innovative facilitations” and “technology-based solutions” abound. Mr Davis boasts in an interview about its “constructive ambiguity”. Yet the paper never escapes from magical thinking.

At no point does it say what it should say: “This is what matters to us.” The paper contains no flesh-and-blood recognition that more than half of the UK’s trade in goods is with EU countries, or that Brexit will affect millions of transactions in goods, their certification of origin and the supply chains of which they are integral parts. The closest it comes to reality is to float the possibility of the UK shadowing the EU’s external border customs policies in UK-EU traded goods.

It does not go further because the obvious policy for British business and British workers is not to shadow the customs union but to remain within it. That, though, is too hot for the Tory party. To open up that issue in that way, even though it is the way that would best defend the UK economy and would involve no change in our trade rules, would set off a Tory civil war that might topple Mrs May. As a result we are witnessing another episode in the lamentable story that has cursed this country’s relations with the EU whenever there has been a Tory government. This latest iteration shows that, in the end, Mrs May is more concerned about getting through the Tory party conference than she is about the future of British trade. The country should be truly indignant about that.

There is, nevertheless, a substantive policy announcement in the customs paper. This is the confirmation of the government’s commitment to what used to be called transitional arrangements, now rebranded as an “interim model” of close association with the EU. Precisely what this will mean in practice is unclear, But it represents a political victory for the chancellor, Philip Hammond, in his efforts to save the government from the prime minister’s insane readiness to take the UK over a March 2019 cliff edge with the EU rather than confront the Daily Mail. It means Mrs May’s earlier claim that no deal with the EU is better than a bad deal is now in the dustbin of history. This is something to welcome in an otherwise confused document.

It is not enough. Instead of taking the bold decisions to change course over Brexit policy, and putting the economy first, ministers have again feebly put their party first. It therefore falls to the opposition parties and sensible Conservatives to work together in every way to defend the public interests that this government seems incapable of defending.