In T 1028/96 of 15 September 1999 date: 1999-09-15 (OJ 2000, 475) the board stated that, in addition to the two admissibility conditions prescribed in Art. 24(3) EPC, the EPC required, as a general rule, that objections be reasoned, i.e. indicated facts and arguments which were alleged to support such an objection. From this requirement it followed, firstly, that an objection based on purely subjective unreasonable doubts should be rejected as inadmissible. It also followed that if facts and arguments filed could not support the objection of suspected partiality raised, the objection was likewise inadmissible (see also T 355/13).
In R 12/09 of 3 December 2009 date: 2009-12-03 the Enlarged Board of Appeal referred to T 1028/96 date: 1999-09-15 and also held that, when determining admissibility, it had to be established whether the objection had been duly substantiated. However, according to the Enlarged Board, this merely meant ascertaining whether it met the minimum standard for objective reasoning, and not whether that reasoning was also persuasive.
In T 1760/11 of 13 November 2012 date: 2012-11-13 the board noted that no reasons were given as to why the fact that the chairman had been employed at Cabinet Regimbeau over thirteen years previously should bias him against respondent 6 or any of the other parties, regardless of whether or not he had in fact acted for respondent 6 during his time there. Such vague and unsubstantiated allegations could not support an objection of suspected partiality
In T 1966/17 the board held that appellant 2's suspicion of partiality of all the board members simply because they did not agree with its submissions and because they expressed a different opinion could not support its allegation of partiality. To the contrary, such reasoning could not be considered to be based on the objective criteria relating to partiality as indicated in G 1/05 of 7 December 2006 date: 2006-12-07 (OJ 2007, 362, point 20 of the Reasons). For this reason alone, i.e. the lack of substantiation, the objection of partiality was found to be inadmissible.
In G 1/21 of 28 May 2021 date: 2021-05-28 the Enlarged Board, having decided in its interlocutory decision of 17 May 2021 that the Chairman of the Enlarged Board and another member of the composition determined by the Chairman should be replaced in application of Art. 24(4) EPC, found the four objections raised by the appellant in the case in hand against members of the Enlarged Board in its new composition to be not admissible (see also in this chapter III.J.3.2). Objection 1 concerned a suspicion of partiality against two regular members of the panel who had previously been objected to. Unlike the initial objection, it was not based on their membership of the Presidium of the Boards of Appeal, but on their possible participation in a meeting with user representatives and their possible role in drafting and presenting the proposed amendment to the Rules of Procedure of the Boards of Appeal. The Enlarged Board found that this objection did not comply with the minimum standard for objective reasoning and substantiation. It was not based on facts ("we have reason to believe...") and the arguments were based on speculation. It was for the party who filed an objection to substantiate it with relevant facts and arguments.
The Enlarged Board also noted that Objections 1, 2 and 4 were not person specific and were very general; they could apply to any board member who took part in internal discussions or meetings with stakeholders (objection 1), all members of the Enlarged Board (objection 2), or all internal members of the Enlarged Board and the Boards of Appeal (objection 4). It found it questionable whether such general und unspecified objections could be seen as an objection of partiality within the meaning of Art. 24 EPC. With regard to Objection 1, the Enlarged Board noted that merely limiting the objection to certain members was not sufficient to make the objection reasoned with respect to the members concerned, and could not plausibly establish that the objection was indeed person-specific. With regard to objection 2, the fact that Art. 24 EPC could not adequately alleviate the unspecific and speculative concerns of the appellant was a strong indication that the mechanism of Art. 24 EPC was not meant for objections that were exclusively based on such general grounds. With regard to objection 4 – which was based on the fact that the re-appointment of members of the Boards of Appeal and the Enlarged Board was inter alia dependent on a positive opinion from the President of the Boards of Appeal, who was also the Chairman of the Enlarged Board – the Enlarged Board noted that the mechanism of Art. 24 EPC was not meant for objections that were exclusively based on such general, institutional concerns and was also not capable of alleviating these concerns. The use of Art. 24 EPC for the institutional concerns expressed by the appellant, when taken to the extreme, could potentially lead to a complete paralysis of the present proceedings.