The new rules are designed to reduce the risk of supplier failures, protect consumers and strengthen the resilience of the energy market. They come after a slew of energy failures in recent months which has seen more than 25 suppliers go bust since September.

The rules will see suppliers undergo financial stress testing. Ofgem will assess suppliers against a range of potential scenarios, such as big wholesale energy price changes, or if a large number of customers were to leave or join in a short space of time. It will test to see if suppliers can manage this.

The regulator will also require supplier boards to undertake a self-assessment to show that they are managing risk properly.