PARIS (AP) — Several thousand conservative activists of all ages marched through Paris on Sunday to protest a French bill that would give lesbian couples and single women access to in vitro fertilization and related procedures.

"Where is my dad?" read some signs as traditional Catholic groups, far-right activists and other marchers weaved from the Luxembourg Garden to the Montparnasse neighborhood, passing by the French Senate.

Police guarded several Paris streets as the protest unfolded, notably to prevent tensions with LGBT activists holding a small counter-demonstration in support of the bill. Both were peaceful.

The conservatives' march was organized by the same groups that held mass demonstrations against France's legalization of gay marriage in 2013, who are hoping their opposition to the IVF bill provides new fuel for their movement.

Some shouting "Liberty, Equality, Paternity" — a play on the national French motto — marchers argued that the bill deprives children of the right to a father. The crowd included parents with children and older people.

"I believe we are going too fast and we're not thinking about the consequences of this law," said demonstrator Monique Brassier of the eastern city of Nancy. "We are heading toward a commercialization of the human being, a commercialization of procreation, and that scares me."

Proponents say women should have the right to bear children regardless of their marital status or sexual orientation, and say the bill's opponents are trying to preserve an outdated patriarchal system.

President Emmanuel Macron's government considers such procedures shouldn't be restricted to infertile, married heterosexual couples as families and society evolve. Several other countries already offer assisted reproduction to lesbians and single women, and French women sometimes travel abroad for fertility procedures.

The measure is part of a broader bioethics draft law under debate at the National Assembly, where Macron's party has a majority.

France's health care system would cover the cost of the procedures for all women under 43.

It also would allow children conceived with donated sperm to find out the donor's identity upon demand when they reach age 18, a change from France's current strict donor anonymity protections.

The new bill doesn't cover surrogate pregnancies, which are banned in France.

"We cannot live without our parents. That's the human condition," said Olivier De La Chapelle from the northeastern city of Metz. "They are making legislation so that a person will not have a father anymore. That's scandalous."

Elaine Ganley contributed to this report.