Re: BT should return ALL the subsidy...
Well, alright, yes. But all divisions are kept isolated by regulation.
I don't believe that, having worked in a couple of much better regulated sectors myself. Because BT and Openreach are one single entity, Ofcom have to rely on management accounts, not statutory accounts. In practical terms that means Ofcom have to believe what they are told, and there's no way of reconciling those to any audited IAS statements.
The only way of working out what is really going on is through having separate company entities, AND making them use their own bank accounts rather than a single corporate pooling cash account. Having said that, government and Ofcom don't want to know what is going on. BT's huge pension deficit can only be paid off if the company continue to enjoy a profitable monopoly, so the last thing the pols and regulators want is visibility on how much cash Openreach is churning up.