An annual anti-abortion rally on Parliament Hill was interrupted Thursday afternoon by two topless protesters yelling "my body, my rules."

Neda Topalovski and Delphine Bergeron rushed the stage where Gerald Cyprien Lacroix, the Cardinal and Archbishop of Québec, was speaking to the crowd. RCMP officers dragged them away and put them in the back of a police van.

The women are affiliated with FEMEN, an international feminist organization known for protesting topless.

The annual protest often attracts counter-demonstrations, but the RCMP usually manages to keep the two groups separate.

The RCMP said the protest drew between 6,000 and 8,000 people. Organizers told CBC News that 23,000 people attended, down from 25,000 in 2013. RCMP last year said about 10,000 to 12,000 people attended.

A spokeswoman for FEMEN Canada, Laurence Bergeron-Michaud, said her organization protested the rally because it doesn't want the religious right setting policy in Canada.

A report on canada.com said at least three Catholic school boards in Ontario paid to send students to the rally. Others told canada.com that the students either fundraised or were sponsored by local religious organizations.

Topless protesters explain

Topalovski and Bergeron said the shocking part about their protest is that they weren't using their nudity in a sexual way.

In an interview on CBC News Network's Power & Politics, Topalovski and Bergeron said they needed to draw attention to their cause when the anti-abortion side is strong with power and money.

"People write about women's rights all the time. Nothing changes in practice," Topalovski told Evan Solomon, host of Power & Politics.

Asked whether a semi-naked protest is the best way to make their case, both said it is.

"You invited us at your show for that, so yes, it's the best way," Bergeron said.

"No one sees a problem when a woman topless is there for selling a car."

Trudeau's new rule

People take part in the "March For Life" anti-abortion protest on Parliament Hill in Ottawa on Thursday, May 8, 2014. (Sean Kilpatrick/Canadian Press) Liberal Party Leader Justin Trudeau sparked a discussion about the rights of MPs in the abortion debate when he said Wednesday that new candidates for the 2015 election will have to be pro-choice

Trudeau said sitting MPs won't have to abide by the rule, but the new ones have to reflect the party's position. There are at least two MPs in his caucus who support putting restrictions on abortion.

Green Party Leader Elizabeth May said her party is the only one that believes votes should never be whipped and that "members of Parliament are elected to represent their constituents and not a bunch of brass behind closed doors.​"

"Justin's only saying something that's probably true in the other parties as well," May said.

May said she and the Green Party believe in "access to safe, legal abortions."

"I believe that there is no doubt that if you're concerned about human life, and I don't doubt for a minute that the people who are against abortions think that they are concerned with human life, but the reality of it is that women's lives were lost when abortions were illegal ... women who for many reasons had no choice but to try to have an abortion illegally."

PM: won't reopen debate

Prime Minister Stephen Harper has repeatedly said the Conservative Party won't reopen the debate on setting legal limits on abortion.

Johanne Brownrigg, a spokeswoman for Campaign Life Coalition​, said she hopes to encourage others to respect life. She said leaders like Trudeau and the NDP's Tom Mulcair, who says all his MPs are pro-choice, are hurting democracy.

"I haven't lost hope in this prime minister because essentially he is the one who is allowing pro-life MPs to be a part of his caucus. That, for all the accusations that he is a dictator and shuts down debate, we have to recognize that he allows enough dissent that they have a robust discussion and debate among themselves and therefore can better represent their own constituents."

Conservative MP Stephen Woodworth, who believes in restricting access to abortion, pointed to Trudeau's argument that the party became pro-choice when he was elected leader. Woodworth said it reminded him of the saying, "The state, it's me."

"I feel very sad for my colleagues in the Liberal Party that democratic procedures and diversity of opinion is giving way to kind of this top-down ideological approach," Woodworth told CBC News.

Mulcair said no New Democrat MP will ever vote against a woman's right to choose.