A group of radical abortion supporters are asking Twitter to prevent pro-life activists from promoting their tweets.

Reproaction, an activist group aimed at "increasing abortion access," is circulating a petition to censor pro-life content on the social media site. The group says Twitter should not have reversed its controversial decision to block a 2017 ad from Tennessee Senate candidate Rep. Marsha Blackburn (R., Tenn.) that featured her discussing Planned Parenthood's organ harvesting operations. The controversy led a Twitter official to apologize to Blackburn during a July House Judiciary Committee hearing on social media bias.

Reproaction said the company was wrong to apologize to the Republican congresswoman. It wants social media sites to apply the ban on Blackburn to other pro-life arguments and activists. Ads like Blackburn's should be purged from Twitter as "dangerous rhetoric" prohibited under the site's ban on "ads making misleading or deceptive claims," according to Reproaction.

"Stop bending to the will of anti-abortion leaders who seek to spread lies and misinformation," the petition says. "Stop the spread of pro-life lies."

One of the groups that has previously been censored by Twitter said the petition is the latest attempt by pro-abortion forces to marshal private companies to silence conservative voices. Susan B. Anthony List, a group that works to elect pro-life women, has seen a number of ads and promoted Tweets restricted by social media sites and radio stations, including one spot that featured a pro-life quote from Mother Teresa. SBA List spokeswoman Mallory Quigley said censorship campaigns are a sign of desperation.

"There is no clearer indication that life is winning than the desire of our opponents to silence us," she told the Washington Free Beacon. "The abortion lobby fears the pro-life movement precisely because our message is true and compelling."

Reproaction did not return requests for comment about the petition and how many supporters it had received. The group paid Twitter to promote a Tweet advertising the campaign. The campaign sparked backlash from pro-life users who said the promoted Tweet ended up in their timelines.

Twitter CEO Jack Dorsey: No apology is needed for removing pro-life advertisements that outright lie about abortion. Sign your name to end anti-abortion lies on Twitter.https://t.co/OmUM5qUsso pic.twitter.com/mkK2laGpyU — reproaction (@reproaction) August 27, 2018

One pro-life user mocked the ad campaign, saying, "you need some help w your ad targeting; I'm a pro life conservative. But I'm glad you wasted money asking me to sign something I never would." Another called the movement "pathetic," adding, "Now you're advertising to me with a NEW tweet? How bad is your targeting? I'm STILL strongly #ProLife."

lol you need some help w your ad targeting; I’m a pro life conservative. But I’m glad you wasted money asking me to sign something I never would. 😂 — Lisa🖤 (@LisaAMoyer) August 29, 2018

The petition is the latest effort by abortion supporters targeting speech from pro-life lawmakers. In recent years Planned Parenthood and NARAL have backed bills that force pro-life pregnancy centers to post signs advertising abortion or face punitive fines large enough to shut them down. The Supreme Court dealt that campaign a severe blow in June when it ruled that California's law was an unconstitutional violation of the freedom of speech.

The law "unduly burdens protected speech," the 5-4 ruling written by Justice Clarence Thomas said. "It imposes a government-scripted, speaker-based disclosure requirement that is wholly disconnected from the State's informational interest."

Similar laws adopted by Hawaii and Illinois are now subject to legal challenges from pregnancy centers and religious groups.

SBA List said abortion advocates can see the writing on the wall for the future of legal restrictions on pro-life activism. Shifting the strategy from government regulation to stifling pro-life speech in the private sector will avoid First Amendment legal challenges, according to Quigley. She added it would be a mistake for companies to take the bait as it would only motivate activists to fight against "censorship and intimidation."

"We will never stop speaking out about the brutality of Planned Parenthood and the abortion industry or cease fighting to protect unborn children and their mothers," Quigley said. "Social media companies should not take part in these bully tactics, either."