It's hard not to see the UK Euro elections as a Brexit Poll, Round 2. Perhaps some voters didn't see it that way, but presumably Brexit party voters did (what else did Brexit Party mean?); and presumably the LibDem & Green swingers did too.
These are the England, Wales, Scotland results (Northern Ireland results not yet available) analysed as if it were a Brexit poll and on the assumption that 100% of Conservative voters were Pro-Brexit and that Labour is split 50/50:
“Split” covers primarily the Labour Party. Evidently there is a large part of the Labour Party that supports a People's Vote; the YouGov poll survey (fieldwork between Dec 2018 and Jan 2019) puts the Labour Split as 71%/21%. Although I have treated a vote for Conservative as a vote for Brexit, the YouGov poll suggests that is only 69% true of Conservative voters.
Taking those two factors into account brings us closer to the picture described in the Jan 2019 YouGov survey, which has Brexit support at 40%, and Remain support at 46%.
|If there were a referendum today on whether or not the UK should remain a member of the European Union, how would you vote?||Total||Con||Lab||Lib Dem|
|Remain a member of the EU||46%||26||71%||84|
|Leave the EU||39%||69||21%||11|
|Would not vote||6%||2||2||1|
Most other parties have an explicit stated position:
|The Brexit Party||31.6%||5,248,533||->Brexit|
|Scottish National Party||3.60||594,553||Remain|
|The Yorkshire Party||0.3%||50,842||Split|
|UK European Union Party||0.2%||33,576||Remain|
|Animal Welfare Party||0.2%||25,232||Remain|
|Women's Equality Party||0.1%||23,766||Remain|
|Socialist Party of Great Britain||0%||3,505||-|