To say you can’t get consent within a circle, means you’ve already tried and failed to find a small step forward that would give you the information that would confirm or release someone’s fears who has been reluctant to consent. Whenever I get stuck in a decision-making process I name the stuckness and ask the circle to do a round and have each person speak to the stuckness. If we really can’t find the way forward, then we pass off the issue to the next broader circle. There are multiple definitions of consensus theory and practice, some of which are similar and some different from consent. The Sociocracy decision-making process tends to emphasize rounds for equivalence rather than popcorn style of speaking which tends to invite debate rather than listening. Sociocracy asks the question do you have any objection rather than the question do you agree.
For more information, check out our handbook Many Voices One Song sections 3.2, 5.5, and 6.10