Seven new companies are collaborating with Team Tempest to develop the next generation of Royal Air Force aircraft.
Set up in 2018, Team Tempest is the alliance of industrial partners working with the Ministry of Defence (MOD) on the UK's £1.9 billion Future Combat Air System (FCAS) project to build a sixth-generation jet, a concept known as 'Tempest'.
The combat aircraft is due to replace the Typhoon by 2035.
Those working on the project have already designed a generator able to deliver unprecedented levels of electrical power, which the Defence Secretary says is a "world first".
Companies joining the Tempest project are: GEUK, GKN, Collins Aerospace, Martin Baker, QinetiQ, Bombardier and Thales UK, along with UK universities and small and medium-sized enterprises (SMEs).
The Defence Secretary Ben Wallace confirmed agreements to collaborate on Team Tempest were signed at the virtual 2020 Farnborough International Airshow.
The UK has already agreed to work with Italy and Sweden on the programme.
"Just two years after Team Tempest was created they delivered a world first," Mr Wallace said.
"It’s no surprise, when you attract the very best of British engineering and design, technological leaps like these are guaranteed.
"That’s why I’m delighted seven more companies have joined this mission to work in collaboration with the MOD, under the Team Tempest banner.
"They will bring the ambition, invention and expertise that will deliver the breakthroughs we will depend on for decades to come.
"These pioneers will strengthen our ability to develop a next generation aircraft and allow us to continue making vital contributions to UK, European and global security."
Together the expanded Tempest team is aiming to develop more than 60 technological prototypes and hopes to hold a number of demonstrations as the project continues.
The aircraft concept for the future fighter jet was revealed at Farnborough International Airshow in 2018.
How will 'Tempest' be used once it enters service?
The jet itself will be either be flown traditionally by pilots or as a drone and the Ministry of Defence has previously said it hopes the Tempest will by 2035 be flying alongside the RAF's fleet of F-35Bs.
The aircraft at the moment remains a concept, rather than a specific design or aircraft, according to BAE Systems.
It is understood pilots may fly a central aircraft, flanked by smaller, less costly, less capable planes which could act as decoys.
Cover image: MOD.