Southampton said on Wednesday that they had appealed against their expulsion from the Championship play-off final as the punishment was "manifestly disproportionate to every previous sanction in the history of the English game".
An English Football League independent disciplinary commission on Tuesday kicked the Saints out after they admitted spying on a training session of semi-final opponents Middlesbrough.
Boro have now been reinstated and are set to face Hull at Wembley on Saturday for a place in the Premier League, with Championship winners Coventry and second-placed Ipswich having secured automatic promotion at the end of the regular season.
Southampton will also be docked four points next season after admitting multiple breaches of regulations related to the "unauthorised filming of other clubs' training" sessions, according to a statement from the EFL.
Saints chief executive Phil Parsons apologised on Wednesday "to the other clubs involved, and most of all to the Southampton supporters", whom he said "deserved better from the club".
Southampton's appeal will be heard by an independent league arbitration panel later on Wednesday.
A club statement added that the Saints "cannot accept a sanction which bears no proportion to the offence".
Southampton highlighted a £200,000 fine ($268,000 fine) imposed on Leeds in 2019 for spying on Derby as evidence of a precedent the EFL should follow in their case.
However, when Leeds were punished, the EFL's regulation 127 -- which specifically forbids clubs from observing an opponent within 72 hours of a match -- did not exist.
It was introduced after Leeds were sanctioned to help clarify what had been an uncertain situation.
