Four of five party leaders courting female voters made their pitch Monday, laying out proposed childcare plans and promises of an inquiry into missing and murdered aboriginal women in pre-recorded interviews played to a panel of women.

The one woman among the leaders, Green Party Leader Elizabeth May, called the cancellation of a planned federal leaders' debate on women's issues a "lost opportunity" — and criticized Conservative Leader Stephen Harper and NDP Leader Tom Mulcair for not agreeing to participate.

The leaders discuss violence against women in the first segment of <a href="https://twitter.com/hashtag/upfordebate?src=hash">#upfordebate</a>. <a href="https://twitter.com/hashtag/elxn42?src=hash">#elxn42</a> <a href="http://t.co/vRwyuyc7ZE">http://t.co/vRwyuyc7ZE</a> —@UpforDebate2015

"Here we were on the verge of having a debate on women's issues for the first time since 1984 and the woman party leader who wants to do it is me, and because two men decide they don't want to participate, it doesn't happen," she said during her pre-recorded interview with journalist Francine Pelletier.

From the start of Monday's event, one leader was conspicuously absent — Harper, whose decision not to attend elicited boos from the master of ceremonies at the start of the livestreamed discussion.

Comedian Jess Beaulieu joked that perhaps Harper would have participated if women bled oil every month.

Here we were on the verge of having a debate on women's issues for the first time since 1984 ... and because two men decide they don't want to participate, it doesn't happen - Green Party Leader Elizabeth May

May, Liberal Leader Justin Trudeau, NDP Leader Tom Mulcair and Bloc Québécois Leader Gilles Duceppe spelled out their policies on issues such as violence against women and institutional sexism.

The debate on women's issues was called off last month after Mulcair withdrew, citing Harper's absence.

May, who has been shut out of the most recent leaders' debate on the economy and is fighting to be included in next week's foreign policy debate, blasted the "male-dominated and testosterone-flooded" atmosphere of the House of Commons. She called for more women elected to public office and stressed the Green Party would make women's issues a priority.

Up for Debate, the organization behind Monday's event, said the new format — which saw pundits discuss the leaders' statements — was its Plan B.

"Women are here and if the leaders don't want to come in person, we're going to have the debate whether they like it or not," said panellist Laurie Monsebraaten, the social justice reporter for the Toronto Star, which sponsored the event.