Since Toronto is using public funds to fund this parade, then every tax payer is entitled to march in that parade! Anti-war marches in the USA often include people and signs from all walks of American life - gays, blacks, anti-war activists, students from all movements, etc, etc. If you want to make your march exclusive to one group, than that group should fund its own march and not use tax-payer money!
Five people killed in car crash near Hebron (Haaretz)
from the article: Anti-Israel group could cost Toronto Gay Pride parade its funding