[Chrysalis]

Cable has no monopoly, its the only provider with a modern local loop but that doesnt make it a monopoly infact they have strict competition.

Phone - BT is a competitor in every area cable covers.
TV - SKY is a competitor and due to its financial strength and ownership of premium channels has an advantage.
Broadband - ADSL providers are all competitors.

BT on the other hand has a monopoly advantage because in almost all non cabled areas it has what you call a local loop monopoly, this local loop was publicly funded and hasnt had any major investment since BT was privatised. Even LLU lines all pay a portion of income to BT plc.

Sky has a monopoly in some areas where no cable and freeview coverage but this will diminish over time when BT vision becomes more common and freeview coverage increases.