A planned federal leaders debate focused on women's issues has been called off, after the NDP confirmed on Monday they won't be taking part. The debate was being organized by an alliance of Canadian women's organizations called Up for Debate.

Tom Mulcair initially committed to the debate, but NDP party spokesperson Anne McGrath confirmed in a Toronto Star article on Monday morning the party would not be taking part.

Earlier this month, Mulcair said he would only attend debates where Conservative Leader Stephen Harper was present, but his public stance on the women's issues debate was unclear until Monday morning.

Jackie Hansen, a spokeswoman for the Up for Debate group, says not enough leaders had confirmed their attendance to warrant a stand-alone debate. The Conservatives said they would not take part in the debate, while the Liberals, the Greens and the Bloc had already confirmed their attendance.  

"We want a critical mass. Not having the current prime minister and the current leader of the opposition present, that's disappointing," Hansen told CBC News. 

The Up for Debate group announced their "plan b" on Tuesday morning. They plan to record one-on-one interviews on women's issues with Mulcair, Liberal leader Justin Trudeau, Green Party leader Elizabeth May and Bloc leader Gilles Duceppe. Harper has not confirmed whether or not he will participate.

The interviews will be released at a Toronto event in late September.

The news ticked off a lot of people on Twitter. Much of the criticism was directed at the NDP.

Several shared Mulcair's tweet from November 2014, where he agreed to the debate.

It had many wondering why the NDP decided to back out.

Twitter reminded us there hasn't been a federal leaders debate on women's issues since 1984.

The leaders of all three major political parties, Liberal prime John Turner, Conservative leader Brian Mulroney and the NDP's Ed Broadbent all attended.


Some thought Harper forced the NDP to back out of the debate. 

Mulcair said a debate without Harper wouldn't make much sense.

And others used it as an opportunity to boast the NDP's record on women.

The NDP are running plenty of female candidates in this election.

NDP MP Megan Leslie blamed it on the other political parties.

In a written statement to CBC News, Leslie said "Mulcair was the first out of the major parties to agree in principle to participate in the debate on women's issues."

"Since the other leaders refused for months to agree to a debate, Tom Mulcair has been working with the "Up for Debate" coalition to find other ways to highlight women's issues through the campaign."

Many agreed that the move would be tough for NDP supporters to defend.