European Parliament elections in the United Kingdom normally attract a low turnout of voters, just 35% last time round in 2014. This week’s poll is being held under protest, so to speak, a condition of the agreement by the EU to defer the UK’s departure until October next.

Since the UK is still a member, it is treaty-bound to hold elections.

Turnout will be high, according to the pollsters, since these elections are being fought as a re-run of the 2016 referendum and voters are greatly engaged over Europe.

There is an extraordinary paradox here: prior to the decision to hold a referendum on EU membership, Europe had not figured strongly in voter priorities – regular surveys showed greater concern about the health service, housing, unemployment and all the other routine issues.

In the 10 years up to 2015, when the referendum date was approaching, fewer than 10% of voters interviewed had chosen Europe as their most important issue in open-ended monthly surveys of British public opinion.

On several occasions, the percentage highlighting Europe as an issue was less than 5%.

The figures suggest that the public had earlier been less obsessed about Europe than the politicians, until the latter decided to have an in-or-out referendum

Once the government had placed the European question on the agenda, the voters began to identify EU membership as a major concern and it has dominated the issue surveys ever since, with more than half the respondents putting it top of the list over the last few years.

But the figures suggest that the public had earlier been less obsessed about Europe than the politicians, until the latter decided to have an in-or-out referendum.

That referendum produced a narrow majority for Leave, and you know the consequences, a paralysed political system unable to take things forward.

There are now millions of people in the UK who feel passionately about Brexit and are deserting their traditional political loyalties

There are lots of lessons. The biggest is the sheer folly of putting such a huge decision to the voters without a clear plan to deal with the outcome: it was always an even-money chance that Leave would win – once the issue was posed, opinion polls showed that public opinion was close to 50:50. The other lesson, given how strongly people still feel is that, once asked and having decided, voters get wedded to the position they took, even if they may not have felt too strongly when the issue first emerged.

Labour is shedding votes too, albeit at a slower pace, to the Greens and the Liberal Democrats, both opposed to Brexit while Labour prevaricates

There are now millions of people in the UK who feel passionately about Brexit and are deserting their traditional political loyalties over an issue which they found unimportant, month after month, for a full decade prior to the referendum.

The two main political parties are casualties, especially the Conservative party which is losing support heavily to the pop-up Brexit party of Nigel Farage. Labour is shedding votes too, albeit at a slower pace, to the Greens and the Liberal Democrats, both opposed to Brexit while Labour prevaricates.

The outcome of the European Parliament vote in the UK may not eventually matter, since those elected relinquish their seats whenever Britain leaves. But if there is a decision to stay, or a series of further extensions, there could be an exotic collection of British members with plentiful opportunities for mischief.

The more immediate consequence of the Conservative party’s electoral decline has been an early end to Theresa May’s premiership.

The music will have to be faced all over again before October by the inheritor of May’s poisoned chalice

She will quit in June it would appear and the available time for serious political decisions devoted instead to a Tory party succession race.

The music will have to be faced all over again before October by the inheritor of May’s poisoned chalice.

If the stakes were not so high it would be fun to watch Boris Johnson as the inheritor, since he did so much to poison the chalice in the first place.

The next Tory leader will be chosen in a postal ballot of Conservative party members around the country, who will pick from a list of two selected by the MPs.

Anything can happen with Brexit

Johnson will win with the members if he makes it on to the list of two and is the clear favourite. Prior to the referendum, when undeclared on the issue, he agonised over a column for the Daily Telegraph and drafted two versions, one pro-Remain and one pro-Leave, opting for the latter.

After leading Leave to victory, he lost the prize of leadership as the Tory party formed a circular firing squad from which only Theresa May emerged intact.

Anything can happen with Brexit. There could be a no-deal crash-out, the whole thing could get called off and there are endless variations, at least in theory, from a soft to a hard Brexit in between. It is astonishing that this full range of uncertainty still survives almost three years after the 2016 referendum. No possible outcome has been eliminated and the uncertainty is causing significant economic damage. With a Brexiteer at the helm, there could be plenty more to come.