When the trainer takes up too much space

If someone from the training team is always the first to speak up in a discussion and speaks for much longer than others, this can result in the participants being less active and more withdrawn. When I sense that this is happening, I react by discreetly pointing out that discussion interventions should be shorter, and if this is not possible, I speak up and voice my concern and need. I would, of course, consult with the other team members beforehand, discreetly (without causing disturbance), to see whether they get the same sense and I would not interrupt unless at least one of them agreed with me.