Imagine what would have happened if Tessio had said that to Sonny.
He also said that the Charter of Rights guarantees free movement. He has no legal authority to prevent more protesters coming into the city. He says police have blocked off some routes into the city, but with a city as large as theirs, there is no way they can block off all access to protesting trucks. The briefing was a big dose of reality for a City Council of Communists who are in an increasing panic as they realize they have no recourse but to get their leaders to negotiate with those icky truckers and farmers.