While various types of lobbying regulation continue to be devised in different political systems in the world, some questions remain relevant from both a scientific and practical point of view. How can we define a lobbying regulation? What are the principles and the practices that should be pursued by a policy of lobbying regulation? And what is the lobbyists' stance on this matter? We propose a wider definition of lobbying regulation, aiming to overcome the traditional exclusive attention to formal pieces of legislation dedicated to lobbyists and lobbying activities. We refer to the philosophies of open government and deliberative democracy to expand the view on the principles of lobbying regulations, pointing out the macro-dimensions that can be encompassed for a more fine-grained understanding of lobbying regulations, considering not only transparency (as commonly done by most analyses thus far), but also the (fair) equality of access of stakeholders to policymaking and the public accountability of policymakers. On the empirical plan, we test our conceptual framework through an analysis of the perspective of the professional lobbying consultancies enrolled in the lobbying register of the Italian Chamber of Deputies, using in-depth semi-structured video interviews to investigate how such specifically relevant players assess lobbying regulation, and what principles and rules/institutional practices are most significant in their view, finding strong support for measures that aim to pursue the other two principles pointed out beyond transparency.