Analysis by the party claims that in the seven days between Christmas Day and New Year, bills will rise by £104,141,465.75 compared with the same period in 2020.
And they said because of the rise in the energy price cap, families will end up paying an extra £195 each over the year.
Sir Ed said: “The Christmas period is already set to be tough, but this is the worst possible gift from the [UK] Government. Once again ministers are leaving hard-working families out in the cold.
“For many the choice between eating and heating will become a stark one this winter – in sharp contrast to the Number 10 parties and Boris Johnson’s posh wallpaper.
“The spike in gas prices is seeing energy bills rise to unprecedented levels. Next year energy bills are projected to rise by at least another £400, possibly an inflation-busting £500 a year.
“Meanwhile, we’ve seen suppliers collapse, and a reduction in competitive prices.
“The Conservatives have totally failed to tackle the problem. They’ve scrapped insulation programmes that would have reduced people’s bills, cut support for the most vulnerable whilst increasing the UK’s dependence on imported gas, making our country more vulnerable too.
“Liberal Democrats are calling for a new long-term home insulation programme to cut bills permanently, end fuel poverty and reduce emissions.
"As this is an emergency, we also need action now so the Government must double and extend the Warm Home Discount to help the most vulnerable households with their heating bills.”
The call follows reports that business secretary Kwasi Kwarteng would hold “emergency” meetings with energy industry bosses to address rapidly rising wholesale gas prices on Monday.
It was reported bosses were likely to ask for tax cuts and the relaxation of green levies.
Fears of runaway household bills in the new year have been mounting since rising gas prices began bankrupting suppliers in September. Since then, prices have risen from 54p per therm of gas to £4.50.
Since 2019, energy suppliers in the UK have been subject to a price cap put in place by Ofgem, limiting the amount they can charge customers. With the rising prices, many say they were paying more for gas than they could charge.
The cap is moved twice a year based on the price of energy and is due to next be changed in April.
The regulator is already consulting on a series of proposals which would mean the biggest overhaul of the price cap since it was launched if implemented next year.