The French Senate on Monday voted to amend a government-sponsored bill proposed by President Emmanuel Macron to fight climate change and preserve biodiversity.

The climate bill seeks to change the constitution to state that France “guarantees environmental protection and biological diversity, and combats climate change.” That key phrase originated as a result of a recommendation from a convention of 150 randomly-selected citizens last year.

The National Assembly overwhelmingly voted in favor of the initiative in March.

The Republican-controlled Senate, however, voted to remove the key term “guarantee” from the phrase, citing concerns that the word implies environmental concerns would take precedence over other constitutional obligations.

Instead, the Senate approved a text saying that France “preserves the environment as well as biodiversity and acts against climate change under the conditions laid down in the Environment Charter of 2004.”

The Senate also voted to amend the original phrase to read: “[The Republic] protects the environment as well as biodiversity and acts against climate change…”

Following the Senate’s amendment, a joint commission between both houses of parliament will convene to compromise on acceptable wording. A government-sponsored referendum requires that both the National Assembly and the Senate be in agreement over the wording.

If passed, the bill would codify French domestic policies regarding green commitments in the fight against climate change by setting legal limits to advertising by fossil fuel companies and mandating “sustainability scores” on food packaging, among other things.

Critics argue that the bill itself is too week. Inside the government, the High Council on Climate—a body established by Macron to advise on climate policy—published an assessment of the bill stating the proposals fail to “fill the gaps in France’s transition to low carbon…” The Citizens Convention for Climate also said the government did a “poor job of translating their advice into law.”

Widespread demonstrations erupted across France on Sunday, with thousands of citizens calling for more ambitious measures for combatting climate change. Macron maintains that climate continues to be one of his most pressing concerns.