The UK Government has approved the purchase of a third F-35B Lightning II operational test aircraft, as part of the joint combat aircraft (JCA) programme.
The approval has reinforced the UK's commitment to the joint strike fighter programme's upcoming operational test and evaluation (OT&E).
UK joint combat aircraft team head Air Commodore Graham Farnell said the UK had, this week, received financial approval to go ahead and purchase the third STOVL OT&E aircraft that is planned within LRIP 4.
"I believe it reflects well on the JSF programme and it is a measure of the confidence that the UK has in both the F-35 Lightning II and the programme to deliver this capability," he said.
A supersonic, multirole, fifth-generation stealth fighter, the F-35 aircraft will transform the Lightning II as the most cost-effective fighter programme.
Three variants of the F-35 aircraft will be derived from a common design, and developed together by using the same sustainment infrastructure across the world.
In the beginning, the variants will replace aircraft in at least 13 services for nine nations.
The approval has come following the recent F-35 down-select or procurement commitments by Australia, Norway, the Netherlands, Italy and the US.
The UK has emerged as the largest contributor among the programme's nine partner nations, by investing $2bn in the F-35's development.
Other JSF partner nations are the US, Italy, the Netherlands, Canada, Turkey, Australia, Norway and Denmark.