Ukraine has had a carbon tax for years

The basis for Poilievre's concerns seems to be a clause in chapter 13 of the modernization agreement between Canada and Ukraine (the new agreement runs to 30 chapters, plus annexes).

"Consistent with Article 13.24, the Parties shall cooperate bilaterally and in international forums to address matters of mutual interest, as appropriate, to … promote carbon pricing and measures to mitigate carbon leakage risks," the agreement states.

Poilievre's insistence that this is meant to "impose" a carbon tax on Ukrainians is also hard to square with the fact that Ukraine has had a carbon tax since 2011.