France's Dassault Aviation on Wednesday accused Airbus, which represents Germany and Spain in the multibillion-euro Future Combat Air System (FCAS) fighter jet program, of seeking to sabotage the project.
Plans for the next phase of a 100 billion euro ($116 billion) development between France and Germany and Spain are widely seen as near collapse amid a worsening spat between the aerospace groups.
"Airbus no longer wants to work with Dassault, full stop. I take note," Eric Trappier, the chief executive of the French aerospace group, told reporters.
"If Airbus continues to make it likely that it won't work with Dassault, the project is dead," he added.
"We are honoring our commitments to the letter," Trappier added. "It is Airbus that is not respecting the initial agreement."
The FCAS program was launched in 2017 to replace France's Rafale jet and the Eurofighter planes used by Germany and Spain.
But the scheme, jointly developed by the three countries, has stalled as disagreements persist between Dassault and Airbus.
The dispute concerns the leadership of the core fighter part of the project to build an interconnected flotilla of crewed planes and armed drones under a common connective cloud.
Trappier said he had proposed changes to rules for the flying demonstrator phase that would clarify Dassault's leadership of the core fighter, including suppliers, while granting Airbus sway over its own areas of responsibility.
Asked repeatedly over the fate of the project, Trappier defended France's record in making high-performance fighters like the Rafale and accused Airbus of wanting a cumbersome Eurofighter-type partnership.
"I have said from the start that I want clear leadership and not just on paper," Trappier said, referring to the crewed fighter component.
Airbus has said existing agreed rules should be maintained.
German Chancellor Friedrich Merz signaled in February that Berlin could abandon the project, saying Germany does not need the same type of fighter jets as France.
Airbus said it would support a proposal to instead build two separate jets if the countries participating in the project requested it.
Trappier however poured cold water on that idea on Wednesday.
"France cannot support the idea of having two aircraft," he said.
The warplane project is often seen as a bellwether of defense and security cooperation between EU powerhouses France and Germany.
President Emmanuel Macron has sought to play down tensions, calling them "business life."
"Should that determine the strategy of states? The answer is no," he has said.
Earlier this week, Paris and Berlin said they had set up a "nuclear steering group" as Macron said France could deploy nuclear-armed aircraft to allied countries to bolster security.