The principle mechanism of this immunity is the granting of the right to corporations to sue governments and agencies of governments that have laws or regulations that impinge on corporate profits. For example, France's prohibitions of GMO foods are, under the "partnerships," "restraints on trade that impinge on corporate profits.

The "partnerships" set up "tribunals" staffed by corporations that are outside the court systems of the sovereign governments. It is in these corporate tribunals that the lawsuits take place. In other words the corporations are judge, jury, and prosecutor. They can't lose. The "partnerships" set up secret unaccountable governments that are higher and have power over the elected governments. 

You can ask yourself how much money the representatives of the countries who "fasttracked" this system were paid by the corporations and how much the bribes will be to get the agreements approved by the legislators. As you witness American, British, German and other government officials agitate in behalf of corporate rule, you will know that they have been well paid.