I posted this on another forum and it was in answer to a person that was riding western wondering how much contact is needed for English..
There is more contact than in western but to define the right amount over the net is difficult. What is strong to a Western rider may not be to me. Western riders are more used to an almost no contact and picking up even a little may "seem" strong to them.
In English the contact should never be leaning nor so constant that it allows the horse to lean. The horse looking for contact should never degrade to any form of lean or hold. To express the right contact in the best terms would be to say you feel the mouth and follow the natural movement of the horse so that the reins become more like an elastic. In essence they ACCEPT the frame of the horse, not create it (generated by the seat)
. The horse should be balanced enough through the seat of the rider that if you threw the reins away for a stride or two no change in position, speed or balance will occur in the horse.
I will regularly move my hand forward in a circular motion releasing any pressure on the rein/mouth and resume contact throughout my ride and nowhere does it make any change to the horse's balance. It simply relieves any pressure for a few brief seconds.