Hi BA6501

I will let you know how we get on. We fly in mid-June so will have to see what happens.

The quote below was taken from the Iberia Express website, but whether or not the ground staff at BHX have any idea about it will remain to be seen. They must have arrangements for Business Class passengers at one of the lounges at BHX...

The following passengers have access:

Our passengers flying Business Class on flights operated by Iberia Express.
Iberia Singular, Iberia Plus Platinum, Iberia Plus Gold, OneWorld Emerald and Sapphire passengers that have a ticket or boarding pass for a flight operated by Iberia Express.