Inflation is likely to increase at a faster pace for the poorest UK households, possibly rising to as much as 14% in October, compared to 8% for the richest families, an economic research body has warned.

It comes as the chief executive of energy regulator Ofgem announced on Tuesday that the default tariff cap is set to increase by another ￡800 in October, adding to an already sharp cost of living squeeze.

The rise constitutes a 117% increase, more than double, of the tariff cap between October 2021 and October 2022, bringing the average annual gas and electricity bills to ￡2,800.

"Now, this is uncertain, we are only halfway through our price cap window but we are expecting a price cap in October in the region of ￡2800," Jonathan Brearley, CEO of Ofgem, told the Business, Energy and Industrial Strategy committee.

"I know this is a very distressing time for customers but I do need to be clear with this committee, with customers and with the government about the likely price implications for October," he added.

In April, the energy price cap already increased by 54%, or nearly ￡700, per year for the average household.

Analysis from the Institute for Fiscal Studies (IFS) warned on Wednesday that the price hikes will disproportionately hit the poorest households, as they spend a much larger share of their total spending on gas and electricity.

The bottom 10% of households in terms of income spend on average almost three times as much of their budgets on gas and electricity compared to the highest-income tenth (11% compared to 4%).

Read more: How to cope with bills out of the blue when you really can’t afford it

In April, the bottom 10% of the population in terms of income faced an inflation rate of 10.9%, which was 3 percentage points higher than the inflation rate of the richest 10%.

The IFS cautioned that this pattern was set to continue. “A more than doubling of prices of gas and electricity will further increase the difference in the rate of inflation experienced by richer and poorer households,” it said.

“Assuming an average rate of inflation of 10%, as currently projected by the Bank of England, the analysis suggests that the poorest households may face average inflation rates of as high as 14%, compared to 8% for the richest households.”

The cap covers consumers on standard variable energy tariffs, rather than fixed tariffs, equating to around 22 million households.

Almost 10 million households could find themselves in “fuel stress” this winter if the price cap rises to around ￡2,800, according to the Resolution Foundation.