Switzerland’s multibillion-franc order for 36 Lockheed Martin F-35 fighter jets is under renewed political pressure following U.S. President Donald Trump’s decision to impose a 39% tariff on Swiss exports. The tariff, more than double the rate on EU goods, has prompted lawmakers across party lines to question whether to proceed with the deal, which was narrowly approved in a 2021 referendum. Critics cite rising costs, with the Swiss government recently warned the aircraft could exceed the planned budget by over 1 billion francs.

Swiss Greens leader Balthasar Glättli, who filed a parliamentary motion in March to cancel the F-35 order, argues the United States has become an unreliable security partner and urges Switzerland to consider a European alternative. Liberal MP Hans-Peter Portmann suggested halting further deliveries and filling defense needs from European suppliers, while acknowledging such a step would need careful review.

President Karin Keller-Sutter has defended the contract, stating that abandoning it would leave Switzerland without an air defense capability. The Federal Council previously recommended rejecting the Greens’ motion, but the tariff decision has intensified debate ahead of the next parliamentary session in September.

The Swiss debate comes as other countries reassess their F-35 plans. Spain has opted for the Eurofighter or Future Combat Air System, while Portugal is reportedly cooling on the U.S. jets. Canada is also reviewing its procurement in light of shifting U.S. trade and security policies.

Lockheed Martin has declined to comment on the political dispute, noting that foreign military sales are handled directly between governments.