Governments perceive UN human rights conventions and the law of the World Trade Organization (WTO) as separate legal regimes. WTO jurisprudence, by contrast, interprets WTO rules as parts of international law and may soon be confronted with legal claims that WTO obligations are to be construed with due regard to the human rights obligations of WTO members. The diverse constitutional traditions of WTO members, and their political opposition to linking WTO law to human rights, make it unlikely that WTO members will respond to the UN proposals for a ‘human rights approach to trade’ by adopting a WTO Declaration clarifying that WTO rules are flexible enough to be interpreted and applied in conformity with the human rights obligations of WTO members (section 1). Following the invitation by WTO Director-General Pascal Lamy to form ‘cosmopolitan constituencies’ in support of global public goods (like a rules-based world trading system), this article makes concrete proposals for the initiative by the International Law Association (ILA) to elaborate an ILA Declaration clarifying the complex interrelationships between trade law, human rights and WTO jurisprudence (section 2). As many human rights arguments presented in trade disputes in the EC Court and in the European Court of Human Rights could likewise be raised in WTO dispute settlement proceedings, the article examines whether the ‘constitutional methodologies’ applied by European courts offer lessons for further ‘constitutionalizing’ trade governance in the WTO in conformity with the human rights obligations of all WTO members.