The commissioner of official languages says federal ministers must tweet in both English and French.

A preliminary report from Graham Fraser concludes that former foreign affairs minister John Baird and Public Security Minister Steven Blaney violated the language laws with unilingual tweets.

Fraser's office says ministers don't have to be bilingual, but when they communicate with the public in their official capacities, they must use both official languages.

The commissioner's investigation followed several complaints.

While the report names both Baird and Blaney, Baird was by far the worst when it comes to bilingual tweets.

The Canadian Press has obtained a copy of the documents, which say that during a two-month span, 181 of Baird's 202 tweets were English-only.