The legal battle in Tickle v Giggle has reached the end of the road.

The High Court has refused Sall Grover and Giggle for Girls special leave to appeal the Full Federal Court’s decision against them. For Grover, that means the case is over: there is no further avenue of appeal.

The decision leaves in its wake a deeply concerning outcome for freedom of speech and association.

Giggle was created as an online space for women. But the courts found that excluding Tickle, a transgender-identifying man, amounted to unlawful discrimination on the basis of gender identity under the Sex Discrimination Act 1984 (Cth).

The outcome has serious implications for Australians who believe that biological sex matters in law and for the freedom to form and maintain associations based on sex.

There is, however, an important legal qualification.

The High Court’s refusal of special leave does not mean it heard a full appeal and endorsed the Full Federal Court’s reasoning.

As legal academic Neil Foster has explained, while the lower court’s decision remains in place, the High Court has not ruled on the central question of what “sex” means under the Sex Discrimination Act.

Interestingly, the High Court specifically addressed a different part of the case, section 7D, which allows certain measures aimed at achieving substantive equality. Foster suggests the way the Court dealt with the application may leave open the possibility of a future case squarely addressing the meaning of “sex” under the Act.

For now, however, Tickle v Giggle is finished. But the legal confusion between biological sex and gender remains.

The Sex Discrimination Act needs to provide a clear and truthful definition of sex and properly protect single-sex spaces and associations. Calls for legislative change have already been made by political figures including Angus Taylor, Tony Abbott and Pauline Hanson.

Whatever future litigation may bring, Australians should not have to spend years in court to discover whether the law permits them to recognise biological sex.

Parliament should correct the deficiencies in the law directly rather than leaving Australians to discover the boundaries of their freedoms through costly litigation.