A grenade lobbed into the customs union debate - BBC News
A leaked document suggests a powerful group of senior Brexiteers sees this week's deliberations as a "breaking point".
As if it wasn't tense enough, 30 pages of arguments against part of the government's policy have emerged, an ultimatum from senior Brexiteers who see this week's deliberations over customs arrangements as a "breaking point".

It will hardly have been welcome in No 10's inboxes on Sunday afternoon, days before the Cabinet Brexit Committee was due to meet and also, worth noting, just days before the local elections, where the Tories are already expecting to do badly.

The document, which I understand has been seen by Brexiteer Cabinet ministers, lobs a grenade into a meeting where it was already expected that some would urge Theresa May to drop one part of her plan.

As I wrote last week there is deep scepticism even among some Remainers in Westminster about how viable the customs partnership is.

Another source memorably remarked that the prime minister is more or less the "last person left in Whitehall" who believes it might work.

While No 10 knows very well that proposal has never been popular with Tory Brexiteers, on whose support the majority-less prime minister depends.

Their calculations have always had to take in the likelihood of if and when the dozens of backbench Eurosceptics would rebel.

But the leak of this document suggests the seriousness with which the powerful, if minority group, takes this issue.

A senior Tory said "the customs partnership is the breaking point", suggesting that if No 10 doesn't do their bidding, they could withhold their support.

Of course the stakes are high on all sides, tempers are hot, and it is not certain that they would deliver on those kinds of threats.

But Theresa May warned in her Mansion House Speech that the UK won't get everything it wants in the EU negotiations.

The time when she has to say that forcefully in negotiations with her own party may be coming fast.

The question is whether that's feasible, one former minister said that Theresa May "already isn't leading the party".

Another told me it's like "the politicians have all gone missing".