In Mario Puzo’s The Godfather, everything went wrong when, during a key negotiation, Don Corleone’s own son “broke rank” and asked him to reconsider the offer he just declined – in front of the other side.
The only thing the other side could have concluded is – the Corleone family is in two minds about this. So the “solution” becomes simple – withdraw from the negotiations, remove the old don, and make a deal with the heir. Nothing personal, just business. BANG.
When tackling a negotiation as a team, only one person should be the designated “pilot” – the one that bears the responsibility for the outcome. They are the only person who can react by expressing new opinions or suggesting moving set boundaries. The other team members are here to help hold the boundaries that the pilot sets, to the best of their ability – but nothing else.
That way, you can all just concentrate on the negotiation at hand, and not try to have additional side-debates going on between your own team. There will be time for debriefing later, but allowing the other side to see cracks in your side’s position will only pile on additional problems and damage.**
If you cannot trust your team to abide by this rule, negotiate alone.** At least that way, you minimize the danger of the deal ending up “sleeping with the fishes”.