There is no requirement in the EPC or in the case law that only unconditional requests to oral proceedings are admissible. It is normal practice to request oral proceedings e.g. only for the eventuality of an imminent adverse decision (see inter alia T 870/93, T 1136/10). According to the established practice of the boards of appeal, a request for oral proceedings on an auxiliary basis is interpreted as a request for oral proceedings unless the board intends to decide the case in favour of this party (see T 3/90, OJ 1992, 737).
In T 344/88 the appellants requested that oral proceedings be held if the opposition division intended to maintain the patent in whole or in part. The opposition division rejected the opposition as inadmissible without appointing oral proceedings. The board found that while it was true that, in rejecting the opposition as inadmissible, no formal decision had been taken to maintain the patent, this was nevertheless the consequence of the decision.
According to the established case law, a party is not adversely affected by a decision to remit a case for further prosecution, and for this reason there is no need to grant an auxiliary request for oral proceedings (see inter alia T 147/84, T 222/87, T 42/90, T 924/91, T 47/94, T 1434/06, T 1367/12, T 1727/12, T 1205/13).
In T 902/04 the board held that, since the opponent's request was allowed, there was no need to hold the oral proceedings which only the opponent had requested on a purely auxiliary basis. See also T 545/08, T 749/15.