Photo: The Canadian Press

The federal Liberals are urging Conservative Leader Andrew Scheer to attend the Ottawa Pride parade this weekend after circulating a video of him speaking out against same-sex marriage during a debate in the House of Commons nearly 15 years ago.

The parade in the national capital takes place Sunday, just a week after Ottawa Mayor Jim Watson came out as openly gay after decades in public life.

Public Safety Minister Ralph Goodale tweeted a video of Scheer's April 2005 speech opposing the Civil Marriage Act, which legalized same-sex marriage in Canada later that year.

"There is nothing more important to society than the raising of children, for its very survival requires it," Scheer said in his speech, delivered about a year after he was elected as the Conservative MP for the Saskatchewan riding of Regina-Qu'Appelle for the first time.

"Homosexual unions are by nature contradictory to this," he said.

"There is no complementarity of the sexes. Two members of the same sex may use their God-given free will to engage in acts, to co-habit and to own property together. They may commit themselves to monogamy. They may pledge to remain in a loving relationship for life," he said.

"In that sense they have many of the collateral features of marriage, but they do not have its inherent feature, as they cannot commit to the natural procreation of children. They cannot therefore be married."

The majority of Conservative MPs voted against the bill, as did a number of Liberal MPs.

The message by Goodale hints at some of the notes the Liberals will strike during the fall federal election campaign, when they hope to keep progressive-minded voters in their camp instead of voting for the New Democrats or the Greens.

The Conservatives responded by saying the Liberals were trying to distract Canadians from the SNC-Lavalin affair and pointed out that many Liberals MPs, including those currently sitting, had at one time or another voted against same-sex marriage.

"Andrew Scheer unequivocally supports equal LGBTQ rights, including same-sex marriage as defined in law," the Conservative party said in a statement.

"He has advocated in the House for marginalized LGBTQ communities around the world," the statement said. "While the Trudeau Liberals will do anything to distract from their record of scandal and failure, Andrew Scheer will continue to share his positive vision to help Canadians get ahead."