Martin Lewis gives final day warning to all energy customers at British Gas, Octopus, Eon, EDF, and OVO

Martin Lewis has issued a last-minute warning to millions of Brits who are energy customers with the likes of Octopus, British Gas, OVO, EDF, and Eon.

People in the United Kingdom have just hours left to follow Lewis' advice, with gas and electric bills set to rise across the UK as a result of something called the energy price cap.

But there is time yet, and you can still save more than £100 on your energy bills if you follow the advice and help handed out by Lewis and his Money Saving Expert (MSE) team.

What is happening to UK energy bills?

Long story short, household energy bills are rising across the UK.

This is a result of the energy price cap, which is set every quarter by the country's energy regulator, Ofgem.

The energy price cap limits the amount that a supplier can charge for their default tariff.

That includes something called the 'standing charge', which is the daily amount you have to pay for your supply, no matter how much energy you use. It also relates to price for each unit of electricity and gas you use, measured in pence per kilowatt hours, or p/kWh.

Currently, the price cap is £1,568. Sadly, that is going up almost £150 per year.

Listen to Lewis (James Stack/BBC/Comic Relief via Getty Images)

When do energy bills go up and can I stop mine from increasing?

You only have hours to make the change, with the energy price cap rising from Tuesday, October 1.

The MSE predicts that the price cap will only come down marginally over the next year, so you can do something called 'fixing' your energy prices. That means the cap will remain where it is now for the next 12 months.

Overall, Lewis thinks this could save you cash with deals out there that are up to nine percent less than what the October 1 price cap.

"If you find a fix for at least two percent less than the new (October to December) price cap (or up to eight percent more than the current cap), it's predicted you'll save over the year compared with staying on the price cap," the MSE website says.

Predictions from analysts at EDF and Cornwall Insight say you will pay 11 percent more in the next year if you stay with the price cap fluctuation, so fixing your bills is the best bet when it comes to saving money. This way, you'll also know your budget is set when it comes to gas and electric.

Fixing your bills is the best bet right now (ITV)

Six Martin Lewis snippets

Lewis has taken to X (Twitter) to give a number of explainers relating to the price cap.

He writes: "While it's called a cap, there is NO CAP on what you pay, what's capped is the standing (e.g. daily) charge and how much they can charge for each unit of gas or electricity you use.

"It only applies to firm's standard, i.e default tariffs, the rest aren't capped, and they can charge more or less.

"All firms standard (capped) tariffs price at or very near the cap max, so its not really a cap. In reality the regulator is setting a fixed price and its charged.

"The wholesale rate used to set the cap are not the spot rates (ie the rate you can buy energy today) as especially with gas we've no storage. The regulator uses long term buy-ahead wholesale rates to set the cap, as its prime focus is energy security.

"On top of the wholesale rates, it then adds a host of factors on it (network costs, distribution etc), including a set amount of profit, to come up with the cap."