The most recent opinion poll results that we can find are as follows:

BMG research – April 11

Conservatives: 27 per cent (- 8).

Labour: 31 per cent (no change).

Liberal Democrats: 8 per cent (- 2).

UKIP: 7 per cent (+ 1).

Change UK: 8 per cent (+ 3).

Brexit Party: 6 per cent.

Other: 10 per cent (- 1).

Hanbury Strategy – April 10. For European Parliamentary elections.

Conservatives: 23 per cent

Labour: 38 per cent.

Liberal Democrats: 8 per cent.

UKIP: 8 per cent.

Change UK: 4 per cent.

Brexit Party: 10 per cent.

Green Party: 4  per cent.

SNP: 4 per cent.

Deltapoll – March 31

Conservatives: 36 per cent.

Labour: 41 per cent.

Liberal Democrats: 7 per cent.

UKIP: 7 per cent.

Green Party: 3 per cent.

SNP: 3 per cent.

Plaid Cymru: 1 per cent.

Other: 3 per cent

Now these results don’t compare like with like.  In the last case, we’ve been unable to find results showing changing share.  In the middle one, the polling refers to European Parliamentary elections.  And there are bound to be other national polls that we’ve missed.

None the less, we have three results with the Conservative share at under 40 per cent.

The period immediately before the earliest one saw the run-up to the last “meaningful vote”, including a round of indicative votes (on March 27) and Theresa May’s original letter requesting extension (March 20).

Evidently, a significant slice of the Tory vote is being taken by UKIP/the Brexit Party, and a smaller share perhaps by Change UK.

We seem to be heading back towards where British politics was between 2005 and 2015: in other words, towards more of a three or four or perhaps more party system, with its effects perhaps constrained by first past the post in Parliamentary elections.

Two factors related to Brexit are central.

The first is reaction against it, of which Change UK is a beneficiary, and the other is for it, and against the failure to deliver it.  The future prospects of UKIP and the new parties will be constrained by how many candidates they can find for elections.

That will be less of a factor in a European Parliamentary poll, if one at all, though it will count a bit in the local elections next month.

Since the October extension is neither long nor short, it is most likely to offer the status quo – namely, a drift towards control by the legislature of the Commons timetable, if May’s deal isn’t passed (and whether or not she is forced out).

A new Tory leader would doubtless come with a new Brexit plan, but wouldn’t have the numbers in the Commons for change.

He or she would thus be pushed towards an autumn election, while pro-second referendum MPs agitated in Parliament for another vote.  The timetable is very tight for either.  We face Brexit stasis.