Paola Chiomante/Greenpeace

Construction of the Maya Train has been controversial in Mexico due to a lack of environmental assessments and concerns over habitat loss.

Conservation groups are suing the Mexican government in order to halt construction on a tourist train through the Maya forest in southern Mexico. Parts of the project have moved forward without the usual environmental assessments.

The "Maya Train" is an important infrastructure project for the administration of President Andres Manuel Lopez Obrador, meant to connect major tourist destinations across the Yucatan peninsula. In November, the president published a decree waiving permitting requirements for priority projects, including the train.

"So they are destroying the Maya forest without any environmental impact assessment at all," said Alex Olivera, a senior scientist and Mexico representative for the Center for Biological Diversity, which filed the lawsuit, known as an amparo, alongside Greenpeace on Tuesday.

It challenges the presidential decree and the legality of permits to construct the controversial fifth section of the train, which cuts through important habitat, including underground rivers, caves and cenotes.

“This Maya train construction is already harming the habitat of jaguars, ocelots, Yucatan spider monkeys and many other imperiled animals,” he said, adding that harms are not only from the tracks themselves, but from walls and other infrastructure that will impede the movement of animals and divide the ecosystem.

The lawsuit alleges that the way the project was authorized violates the Mexican Constitution, including the right to public participation and environmental impact information.

This is not the first legal challenge to the train, and a judge has ordered the suspension of construction. But so far work continues.

If this suit is admitted in the Yucatan court, Oliver said a suspension of the construction project could be granted in the coming days.