More than £26 billion was raised by the Government through sales of public assets, such as Royal Mail, in 2015.
The total, £26.4bn, was more than any other year in history, according to Press Association analysis.
Critics argue assets such as Royal Mail and Eurostar were sold cheap.
Responding to the figures, a Treasury spokesman said: "Central to our plan to fix the public finances is the sale of Government assets to help pay down the national debt and ensure economic security for working people."
Shadow business secretary Angela Eagle said the Government was "flogging off the family silver at record pace" and accused Chancellor George Osborne of "touring China selling off any British asset he could lay his hands on to the Chinese state bank".
According to the analysis, almost half of the total came from the sale of mortgages previously owned by Northern Rock, which brought in around £13bn.
More than £1bn was raised by the sale of the Government's remaining shares in Royal Mail, while a further £757 million came from the sale of a 40% stake in Eurostar.
TaxPayers' Alliance chief executive Jonathan Isaby said ministers were "absolutely right" to identify assets to sell off.
But TUC general secretary Frances O'Grady said the privatisations had "nothing to do with providing economic security".
"Eurostar and Royal Mail were both sold for well under value," she said. "Flogging them off for short-term political gain is short-changing taxpayers."
The previous record was set in 1987, when the privatisation of British Airways, Rolls-Royce and other public assets raised a combined total of £20.7bn in today's prices.
Some £2bn of shares in Lloyds are due to go on sale to the public later this year, while the privatisation of Channel 4 has also been rumoured.
- What assets did the Government sell off in 2015?