A price cap on energy bills could be extended to many more households on low incomes, under plans being considered by regulator Ofgem.
A limit on the cost of gas and electricity for those on pre-payment meters already saves about four million people £80 a year.
This could be extended to about two million others on certain benefits.
The proposals come after a much wider cap in the Conservative manifesto was absent from the Queen’s Speech.
The manifesto had suggested the energy market was not working for consumers and, in a widely-debated move, suggested a tariff cap to protect 17 million people paying standard rates. This would have saved them up to £100 a year.
However, after the election, new legislation required for the cap was missing from the government’s plans for the next two years.
Instead, the government said ministers were “considering the best way” to protect those on the poorest-value tariffs.
Business Secretary Greg Clark wrote to Ofgem to challenge the regulator to use its existing powers to reduce bills.
The announcement from Ofgem lists a range of proposals covering billing and switching.
Dermot Nolan, chief executive of Ofgem, told the BBC: “We’re focusing on plans that we will take forward with some urgency to offer extra protection for some customers.”
That includes “a strong possibility that we’ll extend the price cap currently in place for pre-payment meters to vulnerable customers as well”.
Last year, a landmark investigation by the Competition and Markets Authority concluded that many households on standard variable tariffs were paying too much for their energy.
It calculated consumers were overpaying by up to £1.2bn a year.
This led to a cap – set regionally – on the cost of energy for those on pre-payments meters.
Five of the “big six” energy suppliers raised prices for other customers earlier this year, despite pressure not to do so. Ofgem said such rises were not justified.
Now the regulator has said it will hold a summit in July with consumer groups on how it could extend the pre-payment meter cap to other households.
Citizens Advice has already suggested that two million extra households which receive the Warm Homes Discount should get the same protection, including some pensioners and families with young children.
Other Ofgem proposals include: