Is it possible to lose a badge when the statement for recieving stops being true? By this I mean that I get a badge eg. Electorate, but then it becomes false, beacuse 25% of votes are now not on questions. Do I lose the badge, or they cannot be lost?
No - you do not lose badges you have earned.
Definitive answer by Aarobot over on Meta.SE
No, badges are never taken away. That's part of the site's design.
However, if you no longer meet the criteria for a badge (say your "great question" got busted back down to 99 votes), then you won't earn another one of those badges until you "catch up."
Regular badges never go away. Earned once, you get to keep them. Even if the badge is retired, like "Analytical", which is now replaced by "Informed".
As @Rory Alsop points out, if you no longer meet the criteria for the Good/Nice/Great Question/Answer badges, you will keep them, but you won't earn them again - the next time you earn them, the new badge effectively replaces the old one that you already had.
Tag badges however, can go away. They cannot be replaced in this way, as they are specific to a tag.