Yeah the cops would just think they are your fogs turned on with dull bulbs, basically even though they have been wired up correctly as you would wire any kind of DRL.
I've been warned about having them on too but talked my way out of the hefty fine, but that didn't stop them defecting the car.
 

I wasn't defected for the lights for other things but the cop was playing around with the lights and because I already had the fogs switched on they came on automatically when you turn the main headlights on.
Yeah  thats how mine work (JDM) just the toggle switch but the parkers have to be on for the fog lights to work.
You probably will get fined though because, they will know that you have the option of turning them off.