Tom Boonen looks likely to miss the Tour de France for the second successive year after a French court ruled that it was powerless to make a judgement on his ban, opening the door for Australian Allan Davis to step in.
The Quick Step rider launched an appeal against Tour organiser Amaury Sport Organisation's decision to ban him from the race after the 28-year-old tested positive for cocaine back in April for the second time in a year.
However, the tribunal in Nanterre declared on Wednesday that it was not able to make a ruling on the matter.
Boonen's lawyer insists they have not given up on the hope that the former world champion could take his place in the starting line-up on Saturday and that they will take the case to the Court of Arbitration of the French Olympic Committee.
"The judge has informed us that the French court does not have the legal basis to rule in this case," Jean-Louis Dupont told television station Sporza.
"We're going to work on it, that's a certainty. There's an urgency."
Boonen was banned from the Tour last year after he tested positive for cocaine in May.
Meanwhile, Dutch rider Thomas Dekker is set to miss the Tour after the International Cycling Union began disciplinary proceedings following an anti-doping violation.
The 24-year-old, regarded as one of the peloton's most precocious talents after top-10 placings at Amstel Gold, Fleche Wallonne and Liege-Bastogne-Liege, is under suspicion following results of the biological passport programme which suggested an abnormal haematological profile and the detection of recombinant EPO - a blood booster - both of which would enable an athlete to carry more oxygen.
The UCI's suspicions were aroused by 'blood samples collected from Mr Dekker in 2008 and 2009 (which) demonstrated convincing evidence of the use of the prohibited method of enhancement of oxygen transfer'.
As a result a detailed review was carried out and a urine sample collected in December 2007 was found to contain recombinant EPO (Dynepo).
The news is a blow for Silence-Lotto team leader Cadel Evans, who has finished runner-up in the Tour, which begins on Saturday in Monaco, for the last two years.
A UCI statement read: "The International Cycling Union (UCI) today advised Mr Thomas Dekker that he has committed a potential violation under the UCI Anti-Doping Rules."
"Based on these rules, the UCI has instructed the Monegasque Cycling Federation, to which Mr Dekker is affiliated, to open disciplinary proceedings on this matter."
"The nature of Mr Dekker's haematological profile prompted the UCI to conduct a detailed review of the results of EPO analyses conducted on urine samples taken from him since the commencement of the biological passport programme."
"As part of this review, the UCI requested the WADA-accredited laboratory in Cologne to re-examine the results of a urine sample collected from Mr Dekker in December 2007."
"On 30 June 2009, the Cologne laboratory reported a finding of recombinant EPO (Dynepo) in this sample."
"This result was reported in accordance with new EPO detection and reporting rules approved by the World Anti-Doping Agency in May 2009."
"In accordance with the World Anti-Doping Code and the UCI Anti-Doping Rules, the UCI will make no further comment on this matter until a final decision has been made."