Toronto mayoral candidate Brad Bradford intensified his feud with debate organisers on Thursday, accusing the arts-sector forum of moderator bias one day after he boycotted its candidates' event. His campaign demanded new ground rules for future debates.

Bradford, a city councillor for Beaches-East York, skipped Wednesday night's arts debate, claiming the moderator format was stacked against him. The Toronto Star reported that his empty chair drew criticism from other contenders, who questioned his commitment to municipal cultural funding.

The boycott has become a flashpoint in the crowded race to lead Canada's largest city. Rival campaigns and several arts organisations that co-hosted the forum publicly challenged Bradford's characterisation, stating the moderators had been agreed to by all participants in advance.

Bradford's team said he would continue to appear at forums he considers fairly structured. His campaign is pressing organisers of upcoming debates to disclose moderator selection criteria.

The dispute risks defining his candidacy over process rather than policy, a shift his opponents sought to exploit. Toronto's municipal election campaign has drawn national attention as candidates spar over housing, policing budgets and transit funding, with the arts-sector clash now testing how the field handles debate fairness disputes.