Plans to send Brits to their GP to get a discount on energy bills would leave each family doctor dealing with more than 600 patients in fuel poverty.
The idea, which was branded "demented" by critics, is one of several cost of living proposals drawn up by Treasury officials to present to the new Prime Minister.
With energy bills set to rocket to as high as £6,000 a year, the GP would see if patients need help due to being sick, elderly, or vulnerable and then prescribe them money off.
But analysis by the Liberal Democrats found the idea could put pressure on overstretched doctors and heap misery on patients who already face long waits for appointments.
NHS figures from June show there were already around 2,258 patients per GP in England.
Analysts at Cornwall Insight found that 9.2 million households will be left in fuel poverty due to the price cap rise in October, rising to over 10.6 million in January 2023.
If GPs were to see every person in fuel poverty, they could add visits from 614 patients to their workload, the Lib Dems said.
In the worst hit areas of the country, including Kent and Medway, Bedfordshire, Luton and Milton Keynes, and North West London, doctors would have to see more than 700 fuel poverty patients per GP.
Lib Dem Cabinet Office Spokesperson Christine Jardine said: “Telling people they can get help with their energy bills, but only if they get a GP appointment first, is like offering them a new car, but only if they can pick it up from the moon.
"People are already facing outrageously long waits for a GP appointment when they are ill.
"The last thing they need is being forced to wait even longer to see a GP to get help with their energy bills too."
A government source previously told the Mirror that the proposal was “potentially serious and definitely of interest.”
While the source admitted it would take “a lot more work”, they said it was one to consider.
But Labour said the Government had “lost the plot” as waits to see a GP are already so high - and doctors don’t hold people's financial records.
Shadow Health Secretary Wes Streeting said: “The Conservatives have lost the plot on the cost of living crisis and haven’t got a clue about the level of pressure on the NHS.”
Dr David Wrigley, of the BMA union, said it "beggars belief" that GPs would be asked to take this on alongside autumn Covid and flu jabs, dealing with the pandemic backlog and their already heavy workload.
