It is one of the stark revelations that have been uncovered as part of the Government's responsibility to publish the UK's accounts as if it were a bonafide business.
The figures were released by the Treasury and the Office for Budget Responsibility and show that some £1.13 trillion would have to be found if the Government was to pay up all future public sector pension payments.
The figure is some £332 billion higher than the previous year, although the Government says the majority of the rise has been caused by a fall in bond yields.
It means that the UK's liabilities for public sector pensions are the equivalent of approximately 85% of its gross domestic product.
The coalition Government is facing criticism for trying to reform public sector pensions, but will use these latest figures to argue its case that the current system is financially unstable for UK plc.
Many public sector workers, including nurses and teachers, went on strike last week, with thousands protesting against new pension proposals.
But while the Government is insistent that the plans are vital to shore up the UK's finances, it can do nothing about the millions of civil servants that are entitled to a pension payout that is funded by the taxpayer.
The figures showed the state of the country's finances as on 31 March.
They also showed that the country is holding more than £800 billion of debts in Government guilts and almost 380 billion in 'other liabilities'.
