Well, first off you need "enough" room to safely work inside the panel. That is usually interpreted to be 30-36 inches (or one meter).
Most specs seem to say 36", but I think NEC (which really does not apply to control panels as such) says 30" or maybe 36".
But on the practical side, additional space might be needed for equipment removal, or to bring in test gear.
Another issue is if the aisles between facing cabinets are also used regularly for foot traffic. If so you will need to make them wide
enough that a cabinet door can be open, and someone can still safely walk past.
If doors are facing each other, you will at the very least need enough room to open both facing doors simultaneously.
You can find this information in the Electrical Code in both Canada and the US.
My rule of thumb is - three feet for low and medium voltage, five feet for high voltage - plus extra room required to remove any component completely, when required.