Having finished as runners-up in the French second tier last season, Lens were looking forward to taking their place alongside the elite with Metz and Caen when the new campaign begins in August.
However, financial troubles have dogged their pre-season preparations and the club's place in the top flight has been suspended until the Direction Nationale du Controle de Gestion (DNCG), French football's watchdog, are satisfied with their economic situation.
Lens president Gervais Martel was hoping for a cash injection from Azerbaijani investor Hafiz Mammadov to help meet their targets, but that money has yet to materialise
With the money failing to appear, the club's appeal was rejected on Tuesday, although Lens confirmed they would take their case to the French National Olympic and Sports Committee (CNOSF).
"The Board of Appeal DNCG (on Tuesday) rejected our promotion to Ligue 1," said Lens in a statement.
"Despite guarantees the amount of €18million would be paid via the Bank of Azerbaijan, these funds have not yet arrived in our accounts, so the DNCG commission upheld their decision.
"As per the regulations, Lens will appeal to the CNOSF in the coming days."
Sochaux will continue to monitor the situation closely with the hope that they could be reinstated to Ligue 1 if Lens' latest appeal fails.