German politicians on Wednesday approved the next phase of a project to build a joint European fighter jet with France and Spain, despite Defence Ministry scepticism.
The budget committee in the Bundestag lower house of parliament gave approval to the project, known as the Future Combat Air System, to progress to research and development phases between 2021 and 2027.
A government document seen by AFP said the next steps in the project would cost Germany almost €4.5 billion ($5.3bn).
France and Germany announced plans to build a common fighter in 2017, with Spain joining later.
The plane is slated to replace French-made Rafale jets and German and Spanish Eurofighter planes by 2040.
In Phase 2, France's Dassault Aviation and European plane maker Airbus are to build a demonstrator aimed at testing the reliability of the jet's technology.
Dirk Hoke, head of Airbus Defence and Space, welcomed the committee's vote.
"We see this as a strong endorsement and trust in the programme's ability to develop further European operational and technological sovereignty, whilst strengthening its aerospace industry," Mr Doke said on Twitter.
But critics in Germany warned against hasty approval for the next phase of the project.
Der Spiegel magazine reported in early June that the army's procurement office had written to the Defence Ministry to say the contract "must be renegotiated from a technical and economic point of view" and was "not ready for signing".
The deal "almost exclusively satisfies French positions, to the detriment of German industry", it said.
Dennis Rohde, a politician for the Social Democrats, on Wednesday said his party still had "many questions" about the project and demanded "clear conditions for further progress".
France, Germany and Spain announced in May that they had reached agreement on the next phase of the project, ending months of negotiations over how to share the work and the intellectual property.
The programme also includes drones and an ultrafast communications network called the "combat cloud", which will use artificial intelligence.
The total cost of the programme is expected to be nearly €100bn.