Voting in U.K. Elections......
Who can vote in UK general elections
You can vote in UK general elections once you are on the electoral register and provided that you are also:
<dir><dir>aged 18 or over on polling day
a British citizen, (or a Commonwealth citizen or a citizen of the Irish Republic ) living in the UK)
not legally excluded from voting (for example, if you are in prison)
</dir></dir>Who
can’t vote at a general election
At a general election, the following people can't vote:
<dir><dir>anyone under 18 years old
members of the House of Lords
European Union citizens
citizens of any country apart from the Irish Republic and Commonwealth countries
people serving a sentence in prison
anyone found guilty of breaking election law in the last five years
</dir></dir>My emphasis in red.
Therefore,EU citizens cannot vote at U.K.general elections,neither can Australian or NZ or other Commonwealth countries
unless they are domiciled in U.K., in which case they will also have to be registered in the U.K.electoral register.
Local Elections. Only if you are on the U.K. Electoral Register-which you should not be anyway if you are living in EU or abroad.
It makes sense to me
(From direct.gov.site
HERE)