Orange admitted to MPs that 600,000 users across France had lost internet, TV and phone for hours and even days.
Telecoms regulator Arcep saw a “significant growing degradation in service” and reminded Orange it had a duty to provide a quality national service.
It could be fined up to 5% of its business – possibly €1billion – for missing seven of its 12 obligations, including quick set-up of new lines and prompt response to repairs and complaints.
Orange blames weather and cable thefts but consumer groups noted a lack of spending on the copper network as it was replaced by a faster and more reliable optical service.
Anyone with problems can ask Arcep (jalerte.arcep.fr) for action and compensation.