@Suiseiseki @SuperDicq no. you know working democracies (not the US) have what you call seperation of powers.
There are very narrow circumstances where the executive branch is allowed to make rules themselves. And only where laws passed by the parliament allow them to. Mostly for executive functions since laws do not rule over any edge-case that might come up.
These rules though usually only bind the executive and their doings in narrow circumstances.
Only the legislative is able to pass proper laws that actually change taxes.