This Tweet seems to confirm
Members of the approved list of Tory candidates have been told in an email from CCHQ that the UK "will" be contesting EU elections on May 23rd
— Patrick Maguire (@patrickkmaguire) April 8, 2019
So the chances of the UK participating in the May 23rd euro elections seems to have increased sharply during the day based on information coming out of Brussels.
The real interesting feature is going to be the reaction of the Brexiteers to what seems like a betrayal of the referendum. It wasn’t meant to be this way. We were due to leave on March 29th and that has been allowed to slip.
What’s also interesting is that the party machines have only got into Euro election mode late into the day and there is a lot going on to field candidates. We don’t know yet whether the Independent group or Change UK will have its registration finalised in time to allow itself to be on the Ballot.
In Euro elections everything is based on party lists in specific regions and you do not put your cross by the name of a person you’re choosing but by a party.
No doubt we’ll have to wait for confirmation that this is taking place before will get betting on the actual outcome.