Ann: Second Supplementary Target's Statement to UAC Offer, page-11

It only becomes compulsory if they acquire an interest of more than 90%, however if they get 50% then you enter the complicated situation as a minority shareholder, and are at the whims of the new owner.

How does Iberdrola achieve 50%? Convince UAC to accept their offer and the rest is moot.

The alternative is Iberdrola not going unconditional (I think unlikely), and the situation muddles into a stalemate with IFN continuing to operate in the interim.

The nominee holders are the votes Iberdrola is no doubt pursuing, and depending on the custodians authority, I think it likely they sell on market or accept the offer once UAC has signaled its final intent.

I have completely closed my position into the market premium and moved on, yet ill keep an eye on events.