UEFA have thrown out Legia Warsaw's appeal against their expulsion from the Champions League.
The Polish champions beat Celtic 6-1 on aggregate in the third qualifying round but were consigned to the Europa League after UEFA ruled they fielded an ineligible player during the 2-0 second-leg victory at Murrayfield.
The decision infuriated Legia who claimed the punishment was 'severe in the extreme' and called on Celtic to 'do the honorable thing by stepping aside and allowing them to take their rightful place in the competition'.
The Poles also argued that they should not have been thrown out due to what they referred to as a 'minor administration error' but European football's governing body has stood by their original sanction.
Defender Bartosz Bereszynski was introduced into the match in Edinburgh with just three minutes remaining, but it later emerged he had not been registered in Legia's squad for the previous three games and, as such, had not served a three-game ban imposed for a red card in the final Europa League match of last season.
UEFA ruled the match 'a forfeit' handing Celtic a 3-0 victory which was enough to secure a play-off place against Maribor on the away goals rule.
Maribor, who have won the Slovenian title for the last four seasons, have only made the Champions league group stages on one occasion, 15 years ago, and have lost out at this play-off stage in each of the last two seasons.
Celtic will travel to Slovenia for the first leg on Wednesday August 20, with the return in Glasgow on Tuesday August 26.
