Tensions continue to mount in the Cabinet on the Partnership plan for a Customs Arrangement with the EU

Brexiteers say they told No. 10 this was a line in the sand some weeks ago and only held their fire until the end of the local elections. They are now in full insurgent mode telling the Prime Minister in public what she can do with her Partnership idea.

I mentioned last week how the Foreign Secretary taunted the PM with the idea of a vote at last week’s Cabinet Committee. That, to a senior official, is probably the constitutional equivalent of spitting out your chewing gum onto the Cabinet table blotter.

So what has No, 10’s reaction been like?

There have been moments when the Foreign Secretary has been slapped down in the past. Not today. No 10 sounded like it was very keen to avoid a tussle with the Foreign Secretary on this occasion and that is making Mr Johnson’s like-minded Brexiteers think that the chances of Mrs May pushing the Partnership idea all the way to another Cabinet Committee and a full Cabinet pretty unlikely.

While there is an element of planning to the latest uptick in Brexiteer activity some report it has been spurred on by last week’s local election results. Quite a few Brexiteer Tory MPs have interpreted those results as proof that the Tory core vote is now a Brexit vote. The Party must honour those voters, the logic runs. The European Research Group will be holding another of its regular gatherings later today when this message is expected to be proclaimed again. The meetings, witnesses say, sometimes have the air of a rally more than a parliamentary group meeting.

The ERG and its Cabinet allies are effectively daring the PM to test Parliament’s will in a vote on the Customs Union. The Brexiteers insist they don’t think the government would lose a vote, especially if the PM laid her head on the block for the occasion.

On the subject of last week’s results, here’s a fascinating table that crunches through the numbers from last week’s local elections. They’ve been put together by the political analyst Lewis Baston.

They show the swing in areas where there might be a Con/Lab contest in a General Election. They show a 2014/18 swing to Labour that goes beyond London to some surrounding southern towns. It looks better for the Tories in the Midlands. The picture is mixed in the north of England.