I think the avenue Qantas are chasing is what happens if the retail side of the Virgin placement is not fully taken up. The Foreign Airlines would then be able to take up the shortfall.
As far as I can tell, Etihad has FIRB approval to 19.9%. If they take up the unsubscribed retail placement, their stake could go to 22.2%.
Do they have FIRB approval for 22.2% - I can't find anything. So wouldn't they need FIRB approval?
I presume this is why Qantas is making such a noise, they don't want the FIRB to approve any further increases. this is the only avenue they have to try and stop Virgin.
The last thing Qantas would want is for Virgin to go private as Virgin would then no longer be subject to the raft disclosure requirements as required for public companies.