Italy’s Deputy Prime Minister Matteo Salvini is putting his weight behind a project to develop a high-speed railway connection between Italy and France, saying that the link “must absolutely be built”.

Salvini’s statement of public support contradicts the position by his governing coalition partners – the Five-Star Movement. Salvini has publicly dismissed a cost-benefit report that Five-Star used as the basis for its opposition to the project.

The train-line promises to slash the journey times between Paris and Milan to just four hours, but requires the construction of an €8 billion tunnel through the Alps. The Five Star Movement campaigned on the promise to scrap the project, arguing that it will never recover the cost of the initial investment.

Five-Star’s leftist leader, Deputy Prime Minister Luigi Di Maio, has steadfastly opposed the project, saying it would be an environmental disaster.

Referencing the same cost-benefit analysis used by Five-Star, Italy’s Transport Minister Danilo Toninelli dismissed the project as a “huge waste of public money”.

Salvini and his arch-conservative Lega (League) Party have the support of the European Commission, who back the project.

“Lyon-Turin is an important project not just for France and Italy, but for the whole of Europe,” a European Commission spokesperson recently said.

The project is to be completed by 2025 and the EU has already ear-marked more than €800 million in funding for the construction. In November, the EU said it is ready to raise its contribution to 50% of the overall cost.

Approximately €1.5 billion has already been spent on preparations for the railway to be built. A separate judicial study estimated the cost of pulling out of the project for Italy at €3 billion.