Scottish Power, one of the “big six” energy suppliers, has seen 120,000 households ditch it for rival providers in the past year.

The news was buried in Scottish Power’s Q2 2019 results which also saw the company’s pre-tax earnings in the division including electricity and gas retail fall by 71 per cent to £49m.

Scottish Power blamed the earnings fall on the mild 2019 winter in comparison to 2018, and the impact of the UK Government’s Price Cap.

Other parts of the Spanish-owned energy firm saw earnings up. The renewables division, including its wind farms, saw pre-tax profits up 4 per cent to £213m.

Networks, the division that owns and runs high voltage power lines in southern Scotland, also saw earnings up 4 per cent to £417m.

Keith Anderson, ScottishPower CEO, said: “A milder winter, in comparison to 2018’s Beast from the East, together with the ongoing price cap, has impacted our liberalised business. But a positive performance in renewables and networks at the mid-year reflects ScottishPower’s sustained delivery of innovative and green investments – the wind generation and new infrastructure we need to deliver the UK’s long-term net zero ambitions.

Peter Earl, head of energy at comparethemarket.com, said: “Scottish Power, like some other big six energy providers, is shedding customers, with a further 120,000 customers choosing to leave the company in the first half of the year.

“It seems that the supplier is failing to keep up with the competition from challenger brands – our own research shows that in the last month alone 10.77 per cent of switches through our website were away from Scottish Power. We suspect that the company may have been relying on the energy price cap as an inertia-based retention tool. It is clear from their results, however, that many Scottish Power customers have recognised the best value tariffs can be found by comparing the market and switching their energy provider.”