As far as Brexit is concerned, Labour can agree on what words to say, but is divided over what they mean. The party’s position is to retain “the exact same benefits” of membership of the European Union, with a Brexit that puts “jobs first”.

For Labour’s more Europhile wing, the only way to achieve the first of those objectives is to retain membership of the single market and the customs union. For them, “jobs first” is primarily about the defence of existing jobs. This faction includes the majority of the trade unions and the TUC, as well as a large minority of the Parliamentary Labour Party (PLP) and most Labour members in the country.

For a narrow majority of Labour MPs, however, and a significant minority in the labour movement, the “exact same benefits” must exclude freedom of movement of workers into Britain. They believe that a flexible labour market has depressed pay and conditions for British workers. For them, “jobs first” means increasing the quality, if not necessarily the quantity, of jobs at home.

If these were the only two factions that Jeremy Corbyn had to please, what to propose would be simple, if not easy to achieve. There is the potential for a deal in which the United Kingdom pays an outsized contribution to the EU’s coffers, loses its right to shape the rulings of the European Court of Justice and the European Commission but follows them to the letter. In return Britain is given a trade deal where it enjoys freedom of goods, services and capital without having to accept the free movement of people.

Yet unfortunately for the Labour leader, there is a third group in the party, mostly compromised of “Lexiteers” – left-wingers who see leaving the EU as a necessary prerequisite for fundamentally reshaping the economy. Corbyn feels a sense of obligation to this faction, many of whom backed his first leadership bid in 2015.

This small but significant group, which includes many leading members of Momentum and his champions in the left-wing alternative media, are intensely relaxed about the free movement of people but want a Brexit deal that frees any future Labour government from the jurisdiction of the ECJ, at least in domestic matters. For this group, “jobs first” means a programme of state aid and government intervention to create new, better-paying jobs, and the “exact same benefits” means the freedom to move to and from the United Kingdom, with the freedoms of finance and manufacturers a secondary concern.

Both pro-Europeans and Eurosceptics are well-represented in Jeremy Corbyn’s inner circle and, in this at least, the Labour leader is a mirror-image of David Cameron. The former Conservative leader was more pro-European than much of his party, but willing to indulge Euroscepticism to discomfort Gordon Brown’s ailing government and bolster his leadership.

Similarly, Corbyn is more Eurosceptic than the Labour mainstream, but is happy to adopt a pro-European pose when necessary to secure his leadership and to defeat Theresa May.

Faced with navigating these divisions, Labour’s shadow Brexit secretary, Keir Starmer, could be forgiven for recalling Harold Wilson’s old joke that managing the party was rather like driving a bus: “If you rattle along at great speed everybody inside is too exhilarated or too seasick to cause any trouble. But if you stop everybody gets out and argues about where to go next.”

Labour’s new Brexit policy, announced on 27 August, is to call for a four-year transition period inside the customs union and the single market. The new policy, jointly hammered out by Starmer and the leader’s office, is intended to crush the possibility of a new pro-European party emerging (a threat that has caused genuine unease in the leader’s office). It also bears the imprint of the trade unions, who have been quietly but firmly lobbying Corbyn to trim his sails in a more pro-European direction.

The new policy has a variety of advantages. First, it unites the PLP, which might disagree on the final destination of Brexit but which can agree on the wisdom of taking the scenic route. (Not least because an almighty row awaits when the party gets there.) That the Conservative Party is divided over the length of transition opens up the possibility of defeating or at least embarrassing the government in the Commons. Tory Remainers, with the exception of the veteran Ken Clarke, have abandoned the idea of unpicking the result but are open to a longer period of transition.

Labour’s Brexit position offers ardent Remainers a scarce commodity: hope. If the opposition can force a longer transitional period on the government, it gives pro-Europeans a greater chance of making that transition, essentially, permanent. We might check out, but we never truly leave.

Labour’s general election result helps Keir Starmer: he is free to balance the competing interests within the party without the pressure of it looking too much like an extended audition for the top job. (There is also an emerging consensus among the party’s power brokers on both left and right that the next leader should be a woman, which makes this aspect of his job less tricky than it once was.)

However, the more Starmer and Corbyn succeed in discomforting Theresa May, the more Labour begins to resemble a government in waiting. As a consequence, it will be subjected to less mockery and much greater scrutiny, as it should be.

For now, most Labour members and backbenchers regard Britain’s exit from the EU mostly as a Conservative bruise to be punched. Very few have started to see it as a bitter inheritance for the next Labour government. But before too long we will need to know where the bus is heading.