OTTAWA—Conservative Sen. Denise Batters has been excluded from all Senate committees after challenging Erin O’Toole’s leadership. O’Toole booted the Saskatchewan senator out of the Conservative national caucus last month after she launched a petition aimed at forcing a referendum on his leadership within six months−rather than wait for a scheduled confidence vote at the party’s convention in August 2023. Conservative senators have chosen to keep Batters in their fold, notwithstanding O’Toole’s warning that anyone backing her petition would be kicked out of caucus. Now, however, she has been conspicuously left out of any committee assignments in the upper house. Sen. Leo Housakos, acting leader of the Conservative Senate caucus, has not responded to a request to explain Batters’ exclusion. Batters declined to comment. Until now, Batters has been a prominent presence on various Senate committees, particularly the legal and constitutional affairs committee, of which she had been a member since …