One of the givens of Westminster politics is that a politician will defend his turf.  Liam Fox is a convinced believer in exiting the customs union as well as the Single Market, for reasons that he explained recently on this site.  We agree with him.  But the knowledge that his job would have less scope were Britain to stay in it will scarcely disincentivise his view.

As in Government, so in opposition.  A delicious Shadow Cabinet row has broken out between Keir Starmer who, as a very solid Remainer, wants to keep open the option of staying in the Customs Union, and Barry Gardiner who, as Fox’s shadow…is taking more or less exactly the same position as the Trade Secretary.

In today’s Guardian, Gardiner doubles down on his position, arguing that “as a transitional phase, a customs union agreement might be thought to have some merit. However, as an end point it is deeply unattractive. It would preclude us from making our own independent trade agreements with our five largest export markets outside the EU (the US, China, Japan, Australia and the Gulf states)”.

He also repeats his line that, were Britain to remain a Single Market member, we would become “technically not be a member of the EU, but we would in effect become a vassal state”.  The so-called hardest of so-called hard Brexiteers on the Conservative benches could not put it more vividly.

Gardiner concedes that he too was a Remainer, but must recognise the verdict of the voters.  It may be that he thinks that – were the Government to fall, Labour to take over, and he himself to replace Fox – staying in the Customs Union would clip his Ministerial wings unduly.  But at any rate, a means of proving his free-trading credentials is to hand.

The Trade Secretary was challenged yesterday to eat an American chlorine-washed chicken, the provision of which could be the part of an Anglo-American trade deal.  It is all very silly: have the journalists in question, as Fox asked, never tucked into a chicken while visiting the United States?

But what’s good for the Trade Secretary is good for his shadow.  He too is presumably anxious to get the most comprehensive trade deal possible with Donald Trump’s administration.  Would Gardiner eat an American chlorine-washed chicken? We think we should be told.