From its colonial trading days to reclaiming land from the sea, the Netherlands has a tradition of pushing the limits, but a public backlash over a planned airport suggests that many Dutch have had enough.

With the opening of a second Amsterdam hub delayed by 20 months and counting, political fronts are hardening ahead of a crucial environmental-impact report expected in January. At the center of the dispute is whether the project is justifiable for a country of 17 million people, which already has some of the most intense land use in the world.

Amid concerns over climate change and the emergence of flight-shaming, the issue is straining Prime Minister Mark Rutte’s complex four-party coalition. The Christian Union, the smallest group in the government, has raised the prospect of opposing the opening of Lelystad airport, located on reclaimed land 40 miles east of Amsterdam.

“The Christian Union is not against aviation, but against nuisance for local residents and damage to the environment,” said Eppo Bruins, a lawmaker for the party. “We can only determine whether the airport can be opened if all information is on the table.”

The 160 million-euro project ($178 million)—backed by Rutte’s VVD party—would add dozens of daily flights to the Amsterdam area. That could free space for KLM to continue international expansion at the city’s Schiphol hub, which has reached government-imposed capacity limits.

A process of national soul-searching began after the plan suffered its first of three delays in April 2018. The latest hurdle is the risk to local eco-systems posed by nitrogen-oxide pollution from airplane exhaust. An independent government-appointed commission will deliver its verdict early next year, with the report likely to set off political wrangling in the run-up to elections in early 2021.

“It’s sheer madness to facilitate a new airport in times of climate urgency,” said Suzanne Kroeger, a member of parliament for the environmentalist GroenLinks party, which is in the opposition. “Lelystad will be a failure.”

As Schiphol passengers jostle through crowded terminals and planes queue up for takeoff amid the Christmas travel crush, Lelystad remains a ghost airport. The converted general-aviation airfield has traffic controllers, custom checks and kiss-and-ride parking signs, but no passengers.

On a recent December day, the tarmac was occupied only by a small propeller plane, while a few construction workers performed minor work at the facility, which would still need months to open if and when it gets approval. The airport operator declined requests for an interview and a tour of the facility.

The nearby city of Lelystad is hoping the situation changes soon. The capital of the province of Flevoland sits on land reclaimed in the 1950s and is keen on attracting business to the isolated area.

“Lelystad has a cyclically sensitive economy,” said Janneke Sparreboom, the city official in charge of economic affairs. “The opening of the airport will make it more robust: more employment, more people coming to live.”

National interests are tied to the site becoming a landing pad for low-cost carriers such as EasyJet Plc and Ryanair Holdings Plc and freeing up headroom for Schiphol. Further expansion of Europe’s third-largest hub would help support KLM’s efforts to vie with carriers like Deutsche Lufthansa AG and IAG SA’s British Airways, according to Lelystad supporters.

More than 23 million passengers flew via Schiphol and the other four national airports in the third quarter, according to the national statistics agency. That marks the highest number of quarterly air passengers ever measured, even though growth at the country’s dominant airfield was a mere 0.2%.

The Netherlands has shown that it’s prepared to go to significant lengths to protect its aviation interests. Earlier this year, the Dutch government secretly accumulated a 14% stake in its flag carrier’s parent company Air France-KLM, sparking a spat with France over influence at the group.

‘Indestructible Optimism’

“One thing is very clear and without dispute: the importance of Schiphol as a hub,” said Mustafa Amhaouch, a lawmaker for the coalition Christian Democratic Appeal party, adding that Lelystad is “key” for the development of KLM’s home base. Limiting aviation isn’t a realistic option, and environmental concerns could be addressed by technology advances and the European Union’s Green Deal policies, he said.

Opponents aren’t buying it, arguing that low-wage airport jobs and incremental development don’t justify the environmental cost.

“It is unthinkable and unacceptable to open a new airport in this day and age,” said Leon Adegeest, head of a group that is seeking to block the opening. “The government would be smart in saying we are going to look into what is really best for society.”

For Rutte’s party, that answer is already clear. Infrastructure Minister Cora van Nieuwenhuizen wants to push for the first Lelystad flights next year, despite the brewing controversy.

“My optimism is indestructible,” she said.