Putting aside the Tories’ usual “slippery slope when it’s convenient for us” BS scaremongering, it sounds like Labour’s goal here is to treat BT like a public utility, with all the common-carrier regulation and roll-outs to regions underserved by the for-profit company.
It’s not going to solve all problems associated with BT’s bureaucracy or technology (despite the usual Tory “Nirvana fallacy” demands), but at least it will provide a little more public accountability and (executed with reasonable competence) perhaps provide a model to other Western nation-states.
A more honest Conservative party would have made that its official aspirational motto decades ago.