A flexible approach of the principle of loyalty regarding the evidence in civil matters – Analysis of the judgment of the Plenary Assembly of 22 December 2023

The decision of 22 December 2023 recognizes the admissibility of evidence obtained or produced in an illicit or unfair manner in civil matters, within the limits of respect for the right to evidence. The Plenary Assembly therefore recalls the necessary sovereign assessment of judges regarding the proportionality of the infringement of the conflicting rights. This decision is in line with a series of decisions issued, in social matters, by the Cour de Cassation during the year 2023 questioning the requirement of loyalty of evidence.

In criminal matters, the principle of freedom of proof is set forth by Article 427 of the French Criminal Procedure Code, which provides that, unless otherwise provided by law, offenses may be established by any method of proof, leaving the judge the power to decide according to his/her inner conviction[1].

According to this principle, the Criminal Chamber of the Cour de Cassation held in several significant judgments that the criminal judges could not disregard evidence presented by the parties solely on the grounds that it was obtained unlawfully or unfairly[2].

By a judgment on the 27 April 2007, the Criminal Chamber however added the obligation for judges to verify whether the admissibility of unfair evidence constituted a necessary and proportionate measure for the defense and the protection of the civil party’s rights in accordance with Article 8 of the European Convention on Human Rights[3].

However, the French caselaw in criminal matters aligns with that of the European Court of Human Rights (hereinafter ‘ECHR’), which has stated that respect for the right to a fair trial prevails over the question of the admissibility of unlawfully obtained evidence[4].

Conversely, in civil law, until recently, the judge was bound by the principle of loyalty of evidence[5]. This principle, based on caselaw, aims at ensuring reliability and fairness in the production of evidence in civil matters.

On 22 December 2023, the Plenary Assembly overturned the decision of the Court of Appeal, which had declared certain pieces of evidence inadmissible due to their nature: transcripts of clandestine recordings[6]. The Cour de Cassation thus establishes the principle of the admissibility of evidence obtained unlawfully in civil matters, within the limits of respecting the right to evidence and subject to the judge’s exercise of a proportional control on conflicting rights (I).

This judgement confirms the meaning of the decisions issued by the Cour de Cassation, in civil matters, in recent years which already challenged the principle of fairness of evidence (II).

I. The recognition of the proportionality control in accordance with the principle of loyalty of evidence in civil matters

In the circumstances of the case in the judgment of 23 December 2023, following an informal meeting, an employee was suspended as a precautionary measure before being summoned to a preliminary interview and then dismissed for gross misconduct.

The employee had challenged his dismissal before the labor court and requested that the employer be ordered to pay various amounts. The employer sought to have the employee to pay damages for failure to comply with the notice period and to compensate for commercial damages.

In a judgment rendered on 28 July 2020, the Court of Appeal of Orléans had decided that the dismissal was without real and serious cause, condemning the employer to pay various sums to the employee and had declared inadmissible the evidence obtained through clandestine recordings.

On appeal by the employer, the Social Chamber of the Cour de Cassation ordered on 1 February 2023, the referral of the case to the plenary assembly.

In a cassation judgment, the Plenary Assembly, after recalling the principle that ‘“justice must be rendered fairly based on evidence collected and produced in a manner that does not undermine its dignity and credibility”[7] and that the production of evidence obtained without the knowledge of the person or obtained by trickery or stratagem is inadmissible, makes a reversal of jurisprudence by holding that “in a civil trial, unlawfulness or disloyalty in obtaining or producing a means of proof does not necessarily lead to its exclusion from the proceedings”[8].

In line with European jurisprudence[9], the Cour of Cassation thus admits that evidence obtained unlawfully or unfairly does not automatically result in its exclusion from the proceedings. It emphasizes the need for the judge to assess “the impact on the fairness of the procedure as a whole’ and ‘by balancing the right to evidence and conflicting rights at stake”[10].

In this regard, it specifies the steps of the proportionality control allowing the admissibility of evidence obtained or produced unlawfully or unfairly. The judge must: (i) verify that the evidence is necessary for the defense of the person who produced it, (ii) balance the right to evidence with other rights at stake, and (iii) ensure hat the infringement is proportional to the aim pursued.

II. A gradual departure from the principle of loyalty in the administration of evidence in civil matters

This reversal of jurisprudence puts an end to the primacy of the principle of loyalty, which, for many years in civil matters, has prevailed over the right to evidence, allowing the inadmissibility of evidence obtained or produced unlawfully[11].

It is nevertheless important to specify that mitigations to this principle already existed in the context of labor law litigation, as shown in the judgment rendered by the Social Chamber on June 30, 2004[12]. In this case, an employee had been dismissed for gross misconduct. The Court of Appeal of Colmar had rendered two judgments on April 30, 2001, condemning the employer to pay her sums for overtime hours and related paid leave. The Cour de Cassation had dismissed the appeal lodged by the employer on the grounds that an employee, “when strictly necessary for the exercise of their defense rights in the dispute against their employer, may submit to the court documents of which they became aware in the course of their duties”.

The Social Chamber had already challenged the principle of loyalty of evidence by repeatedly holding that the illicit obtaining of a means of proof do not automatically result in its exclusion from the proceedings.

In 2023 specifically, this challenge was confirmed by the Social Chamber for various means of evidence: video surveillance[13], surveillance through the geolocation of the employee[14], or even the production of photographs extracted from the employee’s Messenger account[15].

The impact of this reversal also needs to be tempered given that, based on the jurisprudential principles developed by the ECHR[16], French civil and social courts have established the principle of admissibility of disloyal evidence, it is only when it is indispensable for the defense of the party who produced it and does not disproportionately harm the interests of the opposing party[17].