Wow! This is the sort of antiquated law you expect to read about on any number of "dumb laws" web sites. Alas, this particular gem is from 1994 and apparently is actually enforced.
Prince Charles and Camilla Parker Bowles may be forced to allow total strangers into their wedding -- commoners who may be allowed to object to the match.

British newspapers reported Monday that under Britain's 1994 Marriage Act, the public must have unfettered access to witness a marriage so they can object if they wish.

That is why, for example, weddings are never permitted in private homes as people who have a legitimate right to object would not know they were taking place.

And wouldn't that be a travesty? I guess my first question is, does it matter if anybody objects? Do they stop the wedding? Or is this just so all your bitter exes can show up and ruin your special day? Might this be one of those times when somebody's (i.e. the bride or groom's) right to privacy trumps someone else's (i.e the bitter ex's) right to free expression?