Pro-life pregnancy centers in California are asking the nation's top court to allow them the First Amendment right to not say what they don't believe.

The centers oppose abortion and attempt to convince pregnant mothers who visit them to give birth to their children.

Pro-lifers say they've also been successful cutting into the bottom line of abortion companies such as Planned Parenthood, which has made them an enemy of abortion-supporting lawmakers in California.

Brad Dacus, attorney and president of Pacific Justice Institute, says abortionists found friends among lawmakers and found a way to punish the pro-life clinics and help abortion clinics.

"So they've adopted this new law," Dacus points out, "that requires all pro-life pregnancy clinics, even though they are not funded at all by the government, to have a large sign advertising where women can get a free or low-cost abortion."

Abortion clinics in liberal California are not required to advertise where women can find a pro-life clinic.

Attorneys for pro-life clinics and a pro-life organization filed a petition on March 20, asking the U.S. Supreme Court to hear their appeal after losing an appeal the 9th Circuit. They are represented by Alliance Defending Freedom, reported The Washington Times.

The 9th Circuit upheld the law last October but other federal courts in three states have struck down similar laws.

"This is a very important case," says Dacus.