I have (as requested) received a postal form for exercising my right to vote. However, I am not clear about the nature of the election.
On the face of it, I am being invited to choose a representative who will sit in the European Parliament. I am not certain how much influence an MEP has. The European Parliament may seem to echo, in concept, the UK Parliament and other, similar European bodies, but the analogy is an imperfect one. The European Parliament does not have legislative initiative, and very much plays second fiddle to the European Commission.
Irrespective of question marks over the pointfulness of MEP elections in the first place, it is not clear to what extent this particular one is simply about selecting an MEP. The 2019 European election was not supposed to take place in Britain at all, being obviated by our exiting the EU. This exit has not happened and it now seems uncertain whether it ever will.
Now that the election is having to take place after all, some of the campaign literature seems to be suggesting that its real purpose is to send a signal about which British party at Westminster one prefers — for the purpose of delivering Brexit, or possibly of preventing it.
There is also a suggestion that the election could be used to send a signal of somewhat larger scope: a kind of protest vote at the failure of the political class to act in accordance with the electorate's wishes — primarily in relation to Brexit, but perhaps also with regard to social and economic policy in general.