Due to not reaching an agreement about Brexit, the United Kingdom is forced to hold European elections a few weeks from now, on May 23rd. The elected members (across the European Union) will be installed as the new European parliament on July 1st; however, if the United Kingdom leaves the European Union before that date, these elections will have been completely unnecessary:
Government sources say if the Brexit process is completed before 30 June, UK MEPs will not take up their seats at all.
Of course, the election will double as a poll, but (in case of a speedy Brexit) there will be no tangible effects. As far as I can tell, this is a rather unique situation, so I was wondering:
Have there been any elections before (preferably on national level) which were not declared invalid (e.g. by a court) yet rendered completely irrelevant by later events?