With regard to the question whether an opposition is inadmissible if the opponent is a "straw man" acting for some other person, the Enlarged Board of Appeal clarified in G 3/97 and G 4/97 (OJ 1999, 245, 270) that the opponent is the person who fulfils the requirements of Art. 99(1) EPC in conjunction with Art. 100, R. 76 and 77(1) EPC (former R. 55 and 56(1) EPC 1973). Filing the opposition renders this person formally the legitimate opponent. The fact that the opponent is acting on behalf of a third party does not render the opposition inadmissible. It is however inadmissible if the opponent's involvement is to be regarded as circumventing the law by abuse of due process. Such circumvention of the law arises, in particular, if:
- the opponent is acting on behalf of the patent proprietor. According to G 9/93 (OJ 1994, 891), a proprietor cannot oppose his own patent; opposition is an inter partes procedure, so the patentee and opponent must be different persons.
- if the opponent is acting on behalf of a client in the context of activities which, taken as a whole, are typically associated with professional representatives, without possessing the necessary qualifications pursuant to Art. 134 EPC 1973 (wording amended). This would be the case if a person not entitled to act as a professional representative were acting on a client's behalf and carrying out all the activities typically carried out by professional representatives, while himself assuming the role of a party in order to circumvent the prohibition on his acting as a professional representative.
However, circumvention of the law by abuse of process does not arise merely because a professional representative files an opposition in his own name on behalf of a client. In any case, the principle of the free evaluation of evidence applies. The burden of proof lies with the person alleging that the opposition is inadmissible. The deciding body has to be satisfied, on the basis of clear and convincing evidence, that such abuse is occurring.
In the light of the above principles developed by the Enlarged Board of Appeal, the previously relevant case law is largely considered no longer applicable (see T 10/82, OJ 1983, 407; T 635/88, OJ 1993, 608; T 25/85, OJ 1996, 81; T 582/90, T 289/91, OJ 1994, 649; T 548/91, T 339/93, T 590/93, OJ 1995, 337; T 798/93, OJ 1997, 363; for details see also "Case Law of the Boards of Appeal of the EPO", 3rd ed. 1998, p. 424 et seq. and 425 et seq.).