CALGARY -- WestJet Airlines Ltd. is going to the Supreme Court of Canada in an attempt to have a proposed class-action lawsuit launched by a former flight attendant thrown out of court.

The airline lost efforts to scuttle the action in both the B.C. Supreme and Appeal courts, but documents filed with the high court say the case raises several questions of national importance.

Mandalena Lewis worked for WestJet for eight years and alleges in her legal action that the employer broke its promise to provide a harassment-free workplace for women.

WestJet claims in its filing that the high court needs to decide if the Canadian Human Rights Commission and Tribunal have exclusive jurisdiction over the claims of sexual harassment in a non-unionized, federal company.

The documents say if the case is allowed to proceed to court, the jurisdiction of the commission and tribunal have effectively been nullified, which couldn't have been the intent of Parliament when they were created.

Lewis alleges in her civil lawsuit that she was sexually assaulted by a pilot while on a stopover in Hawaii in 2010 and that WestJet breached its anti-harassment promise in her contract.

WestJet has denied allegations that it failed to take appropriate action after Lewis reported what happened.

Her lawsuit proposes to represent all current and former female WestJet flight attendants whose employment contract included the airline's anti-harassment promise.