Borrowing hit £16.8bn last month as pandemic support for the economy continues.
Government borrowing last month was the fourth highest for December on record as the cost of supporting the economy through the pandemic continued.
The gap between spending and tax receipts hit £16.8bn in December, slightly smaller than many economists had forecast.
The figure was helped by more housing stamp duty and fuel taxes bolstering the Treasury’s coffers.
However, interest payments jumped largely due to higher inflation.
The Office for National Statistics said interest payments rose to £8.1bn last month, a record for the month and up £5.4bn from a year earlier.
For the financial year to date, borrowing has now reached £146.8bn, the second-highest figure for the period since records began in 1993.
Chancellor Rishi Sunak, under pressure to relax planned tax rises in April, underlined the impact of rising debt repayments in a statement after the figures were released.
He said: “We are supporting the British people as we recover from the pandemic through our Plan for Jobs and business grants, loans and tax reliefs.
“Risks to the public finances, including from inflation, make it even more important that we avoid burdening future generations with high debt repayments.
“Our fiscal rules mean we will reduce our debt burden while continuing to invest in the future of the UK.”
In total, more than 50 schemes have been announced by the UK government and devolved nations to support individuals and businesses during the coronavirus pandemic.
The consensus among economists was that December borrowing would reach about £18.5bn. However, with the rate of inflation set to continue rising until about April, analysts at Capital Economics said further falls were unlikely.
National Insurance (NI) is set to rise in April, piling more cost-of-living pressure on struggling households.
Although Mr Sunak has so far given no signal he will bow to pressure to scrap the rise, Capital Economics said the December figures suggest he “would have enough fiscal room to cancel” the NI rise without too much damage to the nation’s finances.