TORONTO -- Conservative Leader Andrew Scheer has dual Canadian-U.S. citizenship but is in the process of renouncing his American citizenship.

Speaking at a campaign event in Halifax, Scheer told reporters that he received the citizenship from his father, who was born in the United States.

“Like millions of Canadians, one of my parents (was) born in another country,” he said. “I met with representatives from the embassy in August and announced I was renouncing my citizenship and submitted the paperwork to start that process.”

The Globe and Mail first reported on Scheer’s U.S. citizenship on Thursday.

When asked why he never told anyone about his dual citizenship, Scheer replied: “No one’s ever asked me before.”

Scheer was also questioned about why he waited until the eve of the election to begin the process of renouncing his citizenship.

“I was focused on other things,” he said. “I was rebuilding the party, getting ready for the election, working on the platform. It was always my intention do it before the election.”

Scheer added that he has filed taxes in the U.S. A spokesperson for the party had previously said that Scheer has not renewed his American passport as an adult and has never voted in a U.S. election.

Green Party Leader Elizabeth May was born in Connecticut and had her U.S. citizenship revoked in 1978 when she became a Canadian citizen, per the rules at the time. In a statement to CTVNews.ca, May added she would have renounced her American citizenship anyway.

“It doesn’t matter to Parliament, but I think it matters to Canadians,” she said in the statement. “I’m in a position as leader of a federal political party to potentially become the prime minister, and I think it’s important to know that your prime minister has no other allegiances.”

According to the Elections Act, there aren’t any rules prohibiting dual citizens from running as MPs and the same rules apply to those running for prime minister.

The Conservatives have been critical of other leaders’ citizenship status in the past, however.

Scheer himself questioned former Gov. Gen. Michaelle Jean’s French citizenship in an August 2005 blog post, in which he said he has a “few quick questions” about her appointment: “Does it bother you that she is a dual citizen (France and Canada)? Would it bother you if instead of French citizenship, she held U.S. citizenship?”

Jean renounced her French citizenship before taking office in September 2005.

Scheer defended the comments on Thursday, saying: “It was a question I asked my constituents.”

“I asked the question at the time about the fact that she held it and asked my constituents about what they felt about that,” he said.

In a statement, the Liberals said Scheer has been “fundamentally dishonest with Canadians about who he is.”

“Scheer’s hidden his core personal positions, he hid facts about his career and education, and now he’s been caught hiding his American citizenship even while ridiculing others for holding dual citizenship,” the statement reads.

“Andrew Scheer isn’t telling Canadians who he really is. How can Canadians trust him when he talks about what he’ll do, including what he’ll cut?”

In 2015, then-Conservative Leader Stephen Harper blasted then-NDP leader Thomas Mulcair for holding onto his dual French citizenship.

“I’m very clear. I’m a Canadian and only a Canadian,” he said at the time.

Mulcair, who still proudly holds his French citizenship, told CTV’s The Vote that Harper’s team liked to bring up his dual citizenship as way of inferring that he was not squarely focused on Canadian interests.

“It’s something you hear often with various cultural communities and people of different origins, that if they kept their citizenship that they have divided loyalties,” said Muclair, who’s now a CTV News political commentator.

Mulcair added he was surprised to hear of Scheer’s citizenship status, given his prior blog post.

“How is it that Andrew Scheer actually believed this would not come out in the middle of the campaign?” he said. “I don’t know how he’s going to be able to walk away from this thing, especially given the fact he personally attacked Michaelle Jean.”

Mulcair said the Conservatives will likely need to film a series of new attack ads against Justin Trudeau as the slogan “Not as advertised” no longer works.

During the 2008 federal election campaign, Stephane Dion also faced questions from Conservatives about his French citizenship. Dion had received the citizenship through his French-born mother.

With files from Rachel Aiello and Sonja Puzic