Articles Developments in PIL Scholarship

Lis Pendens and Res Judicata under the ELI/UNIDROIT Model European Rules of Civil Procedure

This post introduces the paper by Fernando Gascón and Guillermo Schumann published in Ius Dictum, 5, 2021, The rules on lis pendens and on res judicata in the ELI/UNIDROIT Model European Rules of Civil Procedure. A pre-print version of the article is available here. Many thanks to Guillermo Schumann for the input.


In 2020 the European Law Institute and UNIDROIT approved the European Rules of Civil Procedure (“ERCP”, also called “Model European Rules of Civil Procedure”): a set of rules intended to design a model, or, if preferred, an ideal civil procedure, with the potential to be operational in any European country. In that regard, it could be said that the ERCP aim to be a “Model Code of Civil Procedure” (although the “code” word has been purposely avoided by the Rules’ drafters) for European countries or, in a certain way, a sort of “Code of Best Practices”. Although a soft law instrument, the Rules stand as a unique text reflecting the outcome of an exhaustive and remarkable work of legal comparison by scholars and practitioners all around Europe (see on this point F. Gascón Inchausti, Las European Rules of Civil Procedure: ¿un punto de partida para la armonización del proceso civil?, Cuadernos de Derecho Transnacional, 2021).

The comparison has not only looked into national systems but has also considered existing European legislation and the acquis communautaire, as well as the case law of the CJEU and the European Court of Human Rights. The intention of the drafters has been to spot the best solution to difficulties faced by all legislators when planning a fair and efficient civil process —best practices or best rules approach—.

The paper by Fernando Gascón and Guillermo Schumann is devoted in particular to the rules on lis pendens (Rules 142-146) and res judicata (Rules 147-152), taking into account their mutual functional relationship, but also their interplay with other procedural institutions in the ERCP.

Lis Pendens and Res Judicata in a System in which “All the Pieces of the Puzzle Work Together”

As stated, the ERCP map out a comprehensive model of a declaratory civil procedure in which the different parts of the Rules are interrelated and meant to work as a system on its own. Therefore, the proper understanding of each rule requires looking at it within the structure. Consequently, the solutions provided by a rule can only be considered as “the best” and as a “model” because they have been conceived to operate inside that systematic ensemble.

Lis pendens and res judicata are legal institutions belonging to the “hardcore” of all procedural legal orders and, because of that, they had to be addressed by the ERCP.

Lis pendens, the rules on related actions and res judicata tend, among other, to regulate the relationship between parallel proceedings, with the same or connected subject matters, that are ongoing or that have ended with a final judgment. This is a decisive issue for both domestic and cross-border litigation. Lis pendens aims at preserving the future negative effect of res judicata in cases of proceedings with identical subject matters, while the stay and consolidation of strongly connected proceedings serve the purpose of preserving its positive effect. Therefore, these legal institutions are necessarily connected among them, but also with others such as the very definition of the “subject matter” of the proceedings or the “preclusion of the cause of action”.

A main goal of the ERCP is indeed to provide for a complete and systematic body of rules where  all “pieces of the puzzle work together” in a coherent manner.

The Lis Pendens and Related Actions in the ERCP: A (Quasi) Transplantation of the Regime of Brussels I Regulation (Recast)

The regulation of lis pendens and related actions proposed in the ERCP is based on the Brussels I Regulation (recast) (Articles 29-32) and on the case law of the CJEU on it. The drafters of the ERCP, having in mind that the European provisions are already working within the Union, thus that the national courts are already familiar with them, considered transplantation into domestic litigation as the best option.

It should be noted, though, that the Brussels I Regulation (recast) aims at regulating the European lis pendens within legal orders having different understandings of the notion of the “subject matter of the dispute” – sometimes, of lis pendens itself. The main purpose of the Brussels I Regulation (recast) and of the case law of the Court of Justice is therefore to set up, from a functional perspective, a system capable to operate detached from the conceptual constructs of the member States. To do so, the Court of Justice has shaped autonomous notions as a way to keep the system operating where indispensable: lis pendens is one of these notions.

Moreover, the scope of the Brussels I Regulation (recast) is limited, both because of the legislative competence of the EU and of the scope of the legal instrument itself. By way of consequence, the EU lawmaker had to address a wide range of issues arising in situations of cross-border parallel proceedings with a limited range of legal tools. This has entailed that the CJEU has broadened (or narrowed, as the case may be) the traditional scope of legal institutions conferring upon them functions that are carried out by other means in the internal legal systems of the Member States.

By contrast, the ERCP have the possibility and the purpose of providing for a complete system. In that vein, a quasi-automatic import of the lis pendens rules from the Brussels I Regulation (recast) may not offer the best solution in all circumstances. Not surprisingly, some of the mismatches and shadows already pointed out by academia concerning the regulation of lis pendens in Brussels I Regulation (recast) appear to be present in the ERCP as well.

Having this in mind, the paper by Fernando Gascón and Guillermo Schumann tries to shed some light on how the lis pendens and related actions operate within the system of the ERCP. It examines the function of the lis pendens and its relationship with the subject matter of the proceedings, the priority principle as the general rule for lis pendens in the ERCP, the exceptions to this principle, the related-actions regime and its relationship with the consolidation of proceedings.

The Rules on Res Judicata in the ERCP

There are different ways to understand and establish the boundaries of res judicata in the many legal orders across Europe. Whether the notion is restrictive or broad usually depends on which part of a judgement becomes res judicata: whether only the operative part of it, or also the legal reasoning. There are also important differences regarding the types of judgments that become res judicata.

As has just been said, the rules on lis pendens and on the stay and consolidation of “strongly related” proceedings tend to preserve the future negative and positive effect of res judicata. Because of that, the scope of res judicata inevitably impacts the regulation of those legal institutions.

From this overall approach, the paper examines the concept of finality in the ERCP, the types of judgments that become res judicata, the material, temporal and subjective scope of res judicata and the powers of the court concerning its assessment. Special attention is paid to the attribution of res judicata to judgments on procedural issues — e.g., the CJEU decision in the Gothaer case —, and to the relationship between the material scope of res judicata and the preclusion of causes of action that, with a broader or more limited scope and following diverse conceptual constructions, is known to most European legal orders.


The European Rules of Civil Procedure are an exciting initiative that shows the utility of Comparative Law as a tool to improve the civil justice system and the protection of the citizens’ rights —at the end of the day, this is what it all is about—. They are a unique instrument, which, on the one hand, facilitates self-cognition in that they allow seeing oneself mirrored in the “others”; on the other, they booster the European harmonization of civil procedure on a common basis.

Legal Secretary CJEU Full Professor PIL University of Santiago de Compostela (Spain) Senior research fellow MPI Luxembourg (on leave) Usual disclaimer applies