This is the reply I received to my questions, but not sure it makes it any clearer?
Thank you for your e-mail of 24 October 2023, on behalf of your unnamed constituent, regarding the costs of the UK’s E-7 Wedgetail order. The original order for five E-7 Wedgetail aircraft was signed in March 2019 to provide a technological edge in an increasingly complex battlespace. However, following the 2021 Integrated Review, the Department took the decision to reduce the scope of the E-7 Wedgetail fleet as part of a wider balance of investment across Defence. The E-7 Wedgetail programme will provide a 5th Generation Airborne Early Warning and Control (AEW&C) capability, with a Multirole Electronically Scanned Array, that is interoperable and interchangeable with key allies. It is a step change in capability from E3 Sentry. A three aircraft fleet will still enable the UK to deliver its national and international commitments, including to NATO. It is not correct to say that the Department is paying the same price for three aircraft and their associated equipment as it would for five aircraft. This is due to contractual renegotiations that were undertaken after the Integrated Review decision. The Ministry of Defence (MOD) anticipates overall savings of around £701 million as a result of this decision. The MOD was committed to the purchase of five Multi-Role Electronically Scanned Array (MESA) radar, however in keeping radars 4 and 5, it allowed the Department to offset costs for the provision of spares for the aircraft. I would also take this opportunity to reiterate that the E-7 Wedgetail programme has generated hundreds of skilled jobs in the UK: in Boeing Defence UK programme management; aircraft modification in Birmingham; in the UK Supply chain, including Defence Aids Suite development with Leonardo; and at RAF Lossiemouth through infrastructure construction, aircrew and groundcrew training and aircraft maintenance. I hope this explains the position. Yours sincerely, JAMES CARTLIDGE MP