Are there any laws or precedents for factually incorrect claims made during an election campaign by politicians / reporters? Could a party or individual be fined or imprisoned, or the vote voided?
I'm not asking about misleading or exaggerated claims (since those are obviously a grey area and, sadly, fully expected by the voting public), but assertions which are demonstrably false or something which the person later admits was a lie.
This is inspired by the increasingly famous results-day admission that part of a campaign in the UK's EU referendum was "a mistake" (the numbers used were impossible), so I'm primarily interested in the UK, but also in how it compares with other countries.