The French Senate on Wednesday approved an article allowing gay couples to adopt children, which is part of a proposed gay marriage bill.

Passage came a day after senators voted in favor of expanding marriage to include gay and lesbian couples.

Debate on Wednesday was dominated by conservatives who argued that allowing gay couples to adopt would pave the way for medically assisted procreation (MAP) and surrogacy. In France, medical procedures such as artificial insemination and in vitro fertilization are only available to heterosexual couples who can prove they have been together two years.

The decision to exclude MAP from the draft bill was met with strong criticism from France's gay rights groups.

Opponents of marriage equality, or “marriage for all” as the French refer to it, had pinned their hopes on the bill's adoption clause as the their best possible chance to have the marriage reform rejected.

“If a law passes containing the words 'marriage for same-sex couples,' then there will be artificial reproductive technologies,” an opponent told the UK's The Guardian. “I don't want this law because it's a lie. It's a law that distorts ancestry, it's a law that weakens links.”

France's lower house of parliament, the National Assembly, approved the measure in February.

Debate on the more than 280 amendments filed is expected to last until Friday or Saturday.

(Related: Uruguay parliament approves gay marriage bill.)