First, a Tony Blair speech.  Next, a Peter Mandelson Marr interview.  You can see the idea taking shape.

I’m not suggesting that there is anything so clear-cut as a fully-formed plan.  But Blair is no fool, whatever else you may think of him, and knows the score.  The Conservatives are committed to Brexit.  Labour have an unelectable leader – and a divided constituency.  The Liberal Democrats are not big enough to fill the gap in between.

Some of us have seen this movie before.  But there are differences this time round.  During the early 1980s, a body of Labour MPs was ready to leave the party and join another.  That doesn’t seem to be the case now, at least yet.  And Conservative MPs were unwilling to jump ship (with one exception).

It is unlikely that even an event as momentous as Brexit will cause even one to do so post-2019 – assuming that Britain leaves the EU on schedule.  However, Brexit is an even bigger event than the economic quarrels of 35 years ago, and political parties in western Europe are fragile.

Blair’s speech was the holding-up of a hankerchief to test how strongly the Remain wind is blowing.  He will be back to wave it again.