‘The big six energy suppliers face the prospect of being broken up when the regulator announces a shake-up of the industry today.

A day after Britain’s second biggest gas and electricity supplier, SSE, announced an unconditional two-year price freeze, Ofgem will kick off a process that is likely to involve a full-scale competition investigation into the energy sector.

This will probe whether British Gas, Scottish Power and the other four big-six providers should be broken up into completely separate retail and energy generation businesses. This would address persistent allegations that they are attempting to disguise the profit they make from supplying cash-strapped households by hiding some of it in the accounts of their generation operations. The big six have always strenuously denied any such activity.

The investigation is also expected to cover why the main energy companies typically tend to increase and decrease their prices within a few weeks of one another – which has raised concerns about industry collusion – and to delve into British Gas’ dominating 41 per cent share of the gas market.’

Read more: Ofgem plans competition inquiry ‘to break up Big Six energy firms’