An extra 2.3 million people will be pushed into fuel poverty by energy firm price rises.
The government estimates 4.1 million households will suffer fuel poverty this year.
But Consumer Focus points out that this does not include price rises by British Gas and Scottish Power.
They could force the total number up to 6.4 million.
A household is considered to be in fuel poverty if it spends more than 10 percent of its income on fuel to be able to keep warm.