TikTok suffered a setback before the European Union's top court on [date of opinion], when a senior adviser backed the EU's decision to designate the platform a "gatekeeper" under the Digital Markets Act, according to AOL.com.

The opinion comes from an advocate general at the Court of Justice of the European Union in Luxembourg. TikTok had asked the court to overturn its designation. The adviser recommended dismissing that challenge.

The setback is procedural but significant. Advocate generals' opinions are not binding on the court. Judges of the Court of Justice will deliver the final ruling at a later date. In practice, the court follows the adviser's recommendation in the majority of competition cases.

What does the gatekeeper label require?

The Digital Markets Act imposes strict obligations on the largest digital platforms operating in the EU. Gatekeepers must, among other duties, share certain data with competitors and accept interoperability demands. They also face limits on favoring their own services over rivals'.

TikTok contested the designation. The company argued it does not hold the entrenched market position the DMA targets. The advocate general disagreed, according to AOL.com, and concluded the EU regulator acted within its rights when it applied the label.

Who decided, and what happens next?

The deciding body is the Court of Justice of the European Union, the EU's highest court. The advocate general's role is advisory. The opinion now passes to the full bench of judges.

For TikTok, the stakes are straightforward. A final judgment upholding the designation would lock the platform into the DMA's compliance regime permanently at the EU level. A win, by contrast, would force regulators to justify the label anew.

For practitioners, the practical consequence is equally crisp. Companies advising large platform clients should read the opinion as a signal that the Court of Justice is likely to take a broad view of the European Commission's power to designate gatekeepers under the DMA. Arguments resting on claims of being a market challenger, rather than an incumbent, may face an uphill climb in Luxembourg.

The court has not yet scheduled its judgment. A ruling is expected in the coming months, following the court's standard timeline after an advocate general opinion.