Re-organization of the European Union Emission Trading Scheme—the European carbon market—is a strategic moment when actors come onto the European arena to voice their claims, represent their interests, propose alternative policy solutions and open up controversies for a public debate. By problematizing rules of the carbon market, actors engage in re-drawing boundaries between economics and politics. This paper adopts a constructivist perspective on the studies of markets and examines strategies adopted by the European Commission and the European industrial federation to inscribe their interests into the ETS rules in 2008. Actors provided justifications for their alternative proposals of the European carbon market by constructing an objective market quality—the market efficiency.