Lopez Obrador is again offering a sharp break from the right-wing policies.
Two weeks ago, a pipeline leak in coastal Mexico sent oil gushing into Coatzacoalcos River.
The Mexican government has lost control of the situation and turned the country into a battlefield.
Some 80 participants attended from the U.S., Mexico, Cuba, Brazil, and Uruguay.
The Mexican Electrical Workers' Union scored a victory last week when the government agreed to recognize its leadership and release frozen union funds.
Workers in Mexico are facing repression from the Mexican government and corporations, and more and more working people in Mexico are being driven into poverty.
The Mexican government under President Felipe Calderon, of the right wing National Action Party, has launched a new attack on the militant Mexican Electrical Workers Union.
A controversy has arisen over U.S. agents operating in Mexico, with the full cooperation of the right-wing government of President Felipe Calderon.
Invoking Cesar Chavez, Andrés Manuel López Obrador said, "[F]or us, we should insist and assure that we are heard and that a new social order comes replacing the old."
The new National Security Law would give the military and state security the right to use force on the simple declaration that they constitute a national security threat.