Both Ecotricity and the Co-operative Energy have grown by about 6,000 customers in the last month.
Ecotricity has grown by “about 7 or 8 per cent since the start of October”, and now has 83,000 customers.
A spokesman at Ecotricity said the switching rate over the last month was double the average and in the last week of October “we were getting up to 5 times what we normally would”.
Co-operative Energy has also gained 6,000 customers since the start of October, and expects there to be the same number again who are currently going through the switching process.
A spokesman said: “The switching levels are up a little bit on previous years. Certainly the level of interest has been very high.”
Ovo is expected to have gained a significant number of customers during the last month, but withheld its customer numbers.
In a statement to Utility Week, Ovo said the increase in switches “is definitely a start, but at the moment that is all that it is – a start”.
However, whilst the smaller suppliers are growing, the proportion of consumers moving away from the big six suppliers has remained the same.
Tom Lyon, energy expert at Uswitch.com, said 30 per cent of switches made are to smaller suppliers, which is the same as it was before SSE announced its price rise.
He added that whilst the proportion remained unchanged, there has been a 600 per cent increase in the number of switches and “the smaller suppliers will benefit proportionally from this”.
Lyon also said that “hundreds of thousands” of consumers are now switching supplier and “people are more aware of the alternatives to the big six”.