Martin Lewis revealed a secret way British Gas customers could be saving up to £300 per month on their energy bill. However, there is only one way they can get their hands on the deal and surprisingly, they can’t directly ask for it. So, how do customers make the saving?

Writing to readers in his MoneySavingExpert.com newsletter, Lewis wrote: “Don’t just call up and ask, some of the big firms’ cheapest deals aren’t available that way.

“They are ‘don’t click, don’t get’ deals ONLY available by doing a comparison.”

The experts say there is no better time than now to “get comparing.”

Martin’s top tip is to switch mobile phone providers.

He said: “Lots of deals that easily give enough data and calls for most people cost less than £10 per month, and are across every main network.

“Remember, while there are many different providers, most piggyback off the main four networks, essentially borrowing their network space.”

An easy way to stay on the same network, without worrying about changes in signal, is to “take advantage of new customer deals” and switch to a network that piggybacks off the main four providers.