Green Party Leader Elizabeth May is joining a chorus of concern about a Conservative law that revokes citizenship from convicted terrorists, days after the government used the new provision for the first time.

Speaking to CTV’s Power Play on Tuesday, May said Conservative Leader Stephen Harper embarked on a “very slippery slope” when his government passed Bill C-42, a controversial law that allows Canada to strip dual citizens who are convicted terrorists of their citizenship and deport them. 

“The only grounds on which someone should be stripped of citizenship is if they obtained their citizenship through fraud,” said May. “Once you start the concept that there are different classes of citizenship and sub-citizens are lesser citizens than others, you’re on a very slippery slope.”

On Saturday, Conservative candidate Jason Kenney confirmed that Zakaria Amara, a Jordanian-Canadian and member of the so-called Toronto 18, had been formally stripped of his citizenship

One day later, the Conservatives leaked an audio recording of Liberal Leader Justin Trudeau saying that terrorists should get to keep their Canadian citizenship, as removing it makes citizenship “conditional on good behaviour.” At the foreign policy leaders’ debate Monday night, Trudeau maintained his position, saying that convicted terrorists should be thrown in jail -- not have their citizenship revoked.

May echoed Trudeau’s beliefs Tuesday, adding that Bill C-24 was all about votes from the get go.

“Should people who commit crimes be put in jail for the rest of their lives? Absolutely,” said May. “It (Bill C-24) was about vote getting in this election. It was about dividing people, twisting and spinning and avoiding some fundamental principles of Canadian citizenship.”

May was not invited to take part in Monday night’s debate. She did, however, have lots to say about it, particularly on the exchanges pertaining to climate change. May said Harper’s claim that greenhouse gas emissions have reduced under his government is “not technically correct.”

“Unless Stephen Harper wants to take person credit for the economic downtown in 2008 … he can’t take any credit whatsoever for the reduction in greenhouse gases that occurred in 2008, 2009. And ever since our economy began to recover, our greenhouse gas levels have been rising,” said May. 

According to Environment Canada, annual greenhouse gas (GHG) emissions have fallen twice since 2006. GHGs fell from 761 megatons in 2007 to 741 megatons in 2008, and then again to 699 megatons in 2009. Environment Canada says the reason for the decrease was the global recession. GHGs began steadily increasing again from 2009 to 2013.

May took to Twitter to post her foreign policy positions during the leaders’ debate, as she did during the Globe and Mail debate on Sept. 17. But her performance was significantly poorer on Monday night, according to data from Twitter Canada. May only had 1,144 mentions on the social media platform Monday night, compared to 14,161 during the Globe debate.