Potanina v Potanin (No 6) (Pre-Trial Review) 2026 EWFC 298

Judgment date: 20 October 2026

https://caselaw.nationalarchives.gov.uk/ewfc/2026/298

MacDonald J. Pre-Trial Review concerning the control of expert evidence, W’s further Questionnaire, H’s exhibited affidavits, H’s attendance at final hearing and the trial timetable.

Background and procedural history

In 2018, the wife, Natalia Potanin (‘W’), made an application under Part III of the Matrimonial and Family Proceedings Act 1984 (‘the 1984 Act’) for financial remedies following a divorce from her husband, Vladimir Potanin (‘H’), in Russia in 2014. Following extensive litigation, in 2025 W was granted permission to proceed. See the Financial Remedies Journal’s collection of the decisions and related commentary here: the Potanin v Potanina Collection.

As at the prior judgment in these proceedings of 14 July 2026, W sought an award from the English court ‘capped’ at 50% of the value of:

(i) H’s ultimate beneficial interest in the shares in MMC Norilsk Nickel PJSC held by Interros Invest;

(ii) the dividends paid on those shares since 2014; and

(iii) an alleged former matrimonial home in Russia known as ‘Autumn House’.

Earlier case management decisions

At the First Directions Appointment (‘FDA’) on 16 June 2026, there was no application for expert evidence regarding the valuation of the assets subject to W’s claim. MacDonald J did, however, grant permission for the parties to instruct a Russian law expert Dr Vyacheslavov, as a single joint expert (‘SJE’), given the dispute between the parties as to the position under Russian law and the central role arguments as to the effect of Russian law are likely to have at the final hearing. The approved list of questions can be found at [6]. The court also gave permission for Questionnaires to be exchanged but, inter alia, refused certain questions put forward by W, and limited the temporal scope of the Questionnaires to three years.

Issues

At [2], MacDonald J identified four case management issues for determination at the Pre-Trial Review (‘PTR’) on 9 October 2026:

i) whether W should be given permission pursuant to FPR 25.4(3) to adduce a report commissioned by her from an accountant as to H’s current financial position, derived from material in the public domain;

ii) whether W should be given permission pursuant to FPR 25.4(3) to adduce a report commissioned by her from a Russian lawyer;

iii) whether W should be permitted to file and serve a further Questionnaire directed to H seeking a response to questions she contends have not been answered sufficiently and responses to two additional questions; and

iv) certain ancillary case management directions regarding, attendance at the hearing and the trial timetable.

Held

Issue (i) – report from forensic accountant

At the PTR, W contended that H failed to disclose the precise size and value of IC Interros Invest’s shareholding in MMC Norilsk Nickel PJSC, the dividends received from MMC Norilsk Nickel PJSC since the parties’ separation, and the value of its other assets. W further contended that H had relied on historical acquisition costs and had disposed of assets amounting to c.9.3bn between 2022 and 2024, implying this was done to defeat her claim.

W unilaterally commissioned a report by a forensic accountant, Ms Guiliani, compiled on the basis of publicly available information. MacDonald J held that the report did constitute expert evidence but was not necessary to resolve the proceedings under FPR 25.4(3). His reasons were that Ms Giuliani herself described her conclusions as ‘estimates and approximations’ derived in a limited amount of time on the basis of incomplete information; [19]. In addition to those difficulties, MacDonald J stated at [20] that he was ‘mindful that the conclusions reached in Ms Giuliani’s report do not, in most respects, take the matter very much further’ given, for example, that her conclusion regarding the overall shareholding attributable to the Interros group broadly agreed with the figure advanced by H himself. Lastly, no application for expert evidence in this respect was made at the FDA nor was any application made to adjourn consideration of that issue. For those reasons, MacDonald J declined to give W permission to adduce Ms Giuliani’s report.

Issue (ii) – report of Mr Kulkov (W’s Russian lawyer)

W also unilaterally commissioned a report from Mr Kulkov and sought to adduce it at the PTR pursuant to FPR 25.4(3), relying on Daniels v Walker (Practice Note) [2000] 1 WLR 1382 as applied in GA v EL [2023] EWFC 187. The report was limited to three issues: (i) the question of whether there is a limitation period under Russian law in respect of a claim for division of assets on divorce; (ii) whether W has a claim for alimony under Art 90 of the Russian Family Code; and (iii) whether there are any provisions of Russian law that restrict the H’s ability to make payments pursuant to any order of the English court; [27].

On balance, MacDonald J was satisfied that the report was necessary having regard to the factors set out in Daniels v Walker. As he explained at [35], arguments regarding the effect of Russian law are likely to figure prominently in the determination of W’s application, and although the difference between Mr Kulkov and the SJE in respect of the issues of limitation and alimony could be said to be one of degree, the court may nonetheless need to come to firm conclusions on them. This litigation also involves very large sums, with a gap of billions between the parties’ positions. As such, the justice of the case required the admission of the report. Due to the report’s narrow scope, calling Mr Kulkov to give evidence would not prejudice the trial.

Issue (iii) – Questionnaire

In respect of W’s Questionnaire on H’s disclosure, MacDonald J held that most of the questions had already been answered; [37]. Of W’s two further proposed questions, neither was approved as framed, but the court required H to confirm the precise size of the shareholding. As such, MacDonald J directed that H instead answer the following two questions; [38]:

• what is the current NAV of IC Interros Invest, as distinct from the initial (historical) cost of its holdings?; and
• what is the precise size of IC Interros Invest’s current shareholding in MMC Norilsk Nickel PJSC, in absolute numbers?

Issue (iv) – certain ancillary case management decisions

Exhibited affidavits

H exhibited two affidavits to his statement of evidence. No permission was sought or granted for the filing and serving of the affidavits, and H conceded they included hearsay and second-hand hearsay; [41]. MacDonald J held at [45] that H must obtain permission to file and serve those affidavits if he seeks to rely on affidavit evidence. As the affidavits contain hearsay, H must also file a notice (i) identifying the hearsay evidence, (ii) stating that reliance is to be placed on the hearsay statement and (iii) giving reasons why the witness will not be called (see FPR Part 23 and the Civil Evidence Act 1995). Failing this, H cannot rely on the affidavits, and they will be excluded from the final hearing bundles.

Attendance

W sought to impose a number of conditions on H regarding his attendance at the final hearing; [46]. H is subject to United Kingdom sanctions, and a travel ban prohibits him from entering or remaining in the United Kingdom. MacDonald J found no evidence of H behaving inappropriately when giving evidence in court and declined to dictate where H gives evidence or direct that one of W’s Russian lawyers be present whilst he gives evidence. At [49], MacDonald J excused H’s attendance at court on the days set aside for judicial reading, housekeeping, the opening on behalf of W, expert evidence and closing submissions. His evidence shall be given with his camera on and following his confirmation that he is alone in the room.

Trial timetable

There was a dispute as to the time for cross-examination, and the court fixed the timetable at [51]. It provides for two days of judicial reading, then W’s evidence on 19–20 November and H’s on 23–24 November, then expert evidence (Dr Vyacheslavov and Mr Kulkov) on 26–27 November, and closing submissions on 1–2 December.