The Changing Landscape of Opposition Proceedings: Parties Must Now Put Their Best Foot Forward

On June 25, 2026, the Federal Court (per Whyte Nowak J.) applied its “gate-keeping function” and refused to allow a party to file new evidence on appeal that could have been tendered before the Trademark Opposition Board (“TMOB”). This is yet another reminder that under the current law, parties to trademark opposition proceedings must put their “best foot forward” before the TMOB and should not assume that new evidence will be admitted on appeal even if the new evidence might be material.