That would require the slandered party (a) prove it’s false and (b) demonstrate harm. There is also good reason for most slander and libel law withholding many remedies from public figures and politicians.

In this case, a department of a single-party city-state issued a takedown notice against allegations of election tampering. It is as illegitimate as it is Streisand-effect inducingly stupid.

I think somewhere you have to accept that certain statements aren't true or false. What has changed recently is the willingness of people to view the statements of others as "lying" as opposed to having a different opinion. Unf, when the plaintiff is the government this becomes even more tricky (and I think a reasonable person would conclude that the PAP have used the legal system to supress criticism...I love Singapore, I love LKY...but it is what it is).

The answer is nobody. You have no recourse unless you're in the US or one of the few other states that Facebook will listen to.