From the EU response to the Seal Products panel's second set of questions:
Question 142 (European Union) Please elaborate on the basis for your position regarding de jure and de facto discrimination claims under the GATT 1994 as described in paragraph 79 of the European Union's oral statement at the second substantive meeting.
157. In that paragraph, the European Union seeks to rebut the Complainants' arguments that the analysis under Articles I:1 and III:4 of the GATT 1994 should be different than the analysis under Article 2.1 of the TBT Agreement, in the sense that the objectives pursued by the measure can only be examined under Article XX of the GATT 1994. The European Union maintains that this should not be the case regarding de facto discrimination claims under the GATT 1994.
158. In all recent cases, i.e. US – Clove Cigarettes, US – COOL and US – Tuna II (Mexico), the Appellate Body has referred to the legitimate regulatory distinctions in cases of de facto discrimination only.93 In the European Union’s view, a contrario this implies that in de jure discrimination cases under Article 2.1 of the TBT Agreement, the Defending Member is not given the possibility to justify its measure on the basis of the objectives pursued. This is in line with the stricter disciplines imposed by the TBT Agreement, as compared with GATT Articles I:1 and III:4, where the possibility of invoking GATT Article XX remains open in de jure discrimination cases. Thus, the objectives of a regulation are relevant in order to establish the existence of de facto discrimination as part of the analysis under Article I:1 or III of the GATT 1994. In the case of regulations involving de jure discrimination, the analysis of the objectives would be confined to Article XX. In contrast, Article 2.1 of the TBT Agreement does not leave any room for considering the objectives of a technical regulation which is discriminatory de jure, and this is consistent with the fact that the TBT Agreement lays down more specific and stricter disciplines with respect to measures qualifying as "technical regulations".
I had never thought about a de facto vs. de jure distinction in TBT Article 2.1. Why shouldn't justifications be allowed for de jure measures? Couldn't there ever be a good reason for explicit discrimination under a technical regulation?