Andrew Scheer, the head of Canada's opposition Conservatives, on Friday dropped one of his candidates for the Oct 21 election and faced repeated questions about why he had not revealed that he has dual US citizenship.

Polls show the Conservatives have a chance to beat the ruling Liberals, but his campaign has been on the defensive since Thursday when a newspaper revealed that he is also a US citizen. After the Globe and Mail newspaper broke the news on Thursday, Scheer (photo, above left) said he was giving up his American citizenship.

"It's not a big deal to have dual citizenship here in Canada," he told reporters, who asked him whether he had ever filed taxes in the United States or registered for the US military draft at 18.

Scheer instead took aim at Prime Minister Justin Trudeau, who is trying to recover from images showing him dressed in blackface, and accused him of breaking promises to eliminate the budget deficit and make life more affordable.

"When Canadians are looking at what he is offering this election, they know they cannot trust him," Scheer said.

Trudeau told reporters in Quebec City that Scheer needed to be honest with Canadians about his dual citizenship and noted that he had apologised repeatedly for the blackface incidents.

"Mr Scheer continues to not take responsibility for his choices of the past, his actions of the past, his mistakes of the past," Trudeau said.

In a further setback for Scheer, the Conservative Party announced it had dropped one of its candidates in British Columbia, Heather Leung, for making offensive comments about gays, including that they "recruit" children.

"Heather Leung is no longer representing the Conservative Party of Canada in the riding of Burnaby North-Seymour," the party said in a statement. "There is no tolerance in the Conservative Party for those types of offensive comments."

Her name will still be on the ballot because the deadline has passed to nominate or remove candidates, but she will not receive Conservative support, and should she win, she will not sit with the party caucus in parliament.

Separately on Friday, the federal government said it would appeal a human rights ruling last month that ordered Ottawa to compensate aboriginal children who had been removed from their homes and put into welfare.

Trudeau told reporters that while he agrees with the idea of compensation, the government needed time to consult with its partners. Such talks could not take place during an election campaign, he added.