All eyes are on Labour and its leader's big Brexit speech on Monday.

It's easier at this point to list the Shadow Cabinet ministers who haven't publicly called for the United Kingdom to remain in some form of customs union with the European Union after Brexit - Nia Griffith, the shadow defence secretary, became the latest minister to do so yesterday when she addressed the trade union Prospect. John McDonnell has described the party's position as "evolving". Is Jeremy Corbyn set to follow suit?

Well, sort of. One of the most commonplace mistakes people make at Westminster is to say that Labour's strategy and objectives for Brexit are unclear, but this isn't quite true. The leadership's strategy is to win the next election and its objective is as big a breach from the European Union as it can pull off while doing so.

He might have a new suit and be a dab hand at shareable videos, but underneath it all, Jeremy Corbyn is still the same man who voted against the constitutional underpinnings of the European Union in 2007, who told the New Statesman he hadn't "closed his mind" to backing Brexit. But while Corbyn is a Eurosceptic by instinct, he doesn't have religion on the issue. Foreign policy is his passion project and like most Labour MPs, he doesn't really regard the EU as "proper abroad". He knows, too, that his best opportunities to damage, defeat and ultimately replace the Conservative government will come over Brexit.

There is a concern in the leader's office that Monday's speech is already been overhyped. What I'm reliably informed will happen is a small, but significant change in the party's position that allows the Opposition to explain why it is voting against the government as far as the customs union goes. The real reason, of course, is that Team Corbyn think this is an area where they can defeat the government.