It is also my understanding that the commonality with the RAAF Wedgetails is extremely high - wise heads want(ed) to ensure the UK was on the same upgrade pathway as the RAAF so the E-3 divergence fiasco isn't repeated.
However, the UK Defensive Aids System will be delivered by Leornado, with Thales sub-contracting for its Elix-IR Threat Warning System. The Leonardo system is, I understand, a newer version of the Electronic Warfare Suite Controller already fitted to the RAAF's Wedgetails. So I would think/hope that at some point that both AFs will be using the same version.
Asturias - Boeings words not mine hence the quote marks. I am in no position to make such an assessment.