Prime Minister Justin Trudeau's main rival in Canada's upcoming national elections, Andrew Scheer, said Thursday he is "pro-life" after weeks of ducking questions on his abortion stance.

The Conservative leader, who is a devout Catholic and married with five children, has said since the start of the campaign that if elected he would shoot down any attempts to legislate a ban on abortion.

But he equivocated when pressed publicly for his personal views on the issue, including when it repeatedly came up in a debate with Trudeau and other party leaders Wednesday evening.

"Personally, I'm pro-life," he finally told reporters at a campaign stop in eastern Canada.

On Wednesday in response to pointed questions from Trudeau - who has cast himself as a champion of women's rights - Scheer kept falling back on a rehearsed line: "I won't reopen this divisive debate."

Pundits said Scheer's stubborn refusal to give a clear answer was hampering his campaign. "Hard night for Scheer," shouted a headline in the Journal de Montreal.

The Liberals and Conservatives are neck and neck in the race to the October 21 ballot. But it is largely attributable to the Liberals losing support to leftist parties, while Tory support has remained stagnant.

Canada legalised abortions in 1969 but they only became widely available after the Supreme Court in 1988 struck down all restrictions.