Councils have been accused of ducking difficult choices by racking up liabilities worth more than £180 billion instead of cutting costs.

L ong-term obligations, such as pensions and loans, that local authorities are facing went up by 8% in the 2012/13 financial year, according to the TaxPayers' Alliance (TPA).

Its study found that 62 local authorities had liabilities worth the same or more than their long-term assets, including Birmingham City Council and Liverpool City Council.

The organisation said Birmingham was wasting money on costly schemes, such as paying contractors £2,000 for every sapling they planted in 2013, while running up £6 billion in liabilities - a claim the council rubbished as "misleading".

Local government representatives dismissed the findings of the report and said that council borrowing was used to fund major infrastructure projects such as building new transport links.

TPA chief executive Jonathan Isaby said: "It is nothing short of immoral for councils to pile further debt on the next generation.

"Britain's public finances are in real trouble, and local authorities can no longer avoid tough choices by putting the bill on the taxpayers' credit card.

"Councils must look again at overgenerous pensions and wage a war on waste, or Britain's debt burden may soon become too heavy to bear."

Long-term borrowing accounted for around £72 billion of the £180 billion bill, which works out at around £2,828 per person in the UK, it said.

A Birmingham City Council spokesman said: "As the largest local authority in the country, it is inevitable we will come at the top of tables based on such research.

"The pension liability, dictated by the financial markets, makes up a significant share of the overall liability, and this share is the sum that would have to be paid out if every single member of the pension scheme was paid their whole pension on exactly the same day.

"The pension liability is falling year on year.

"The claims on the cost of trees are wholly misleading.

"The figure quoted relates to the cost of a tree over its entire life cycle, covering all aspects of its maintenance.

"We have not paid the amount quoted for a tree.

"Prior to our current highways contract, the cost of a tree was not budgeted for in this 'whole life' way, meaning our long-term financial planning now takes this into account more accurately."

A Local Government Association spokesman said: "This is yet another misleading report by the TaxPayers' Alliance.

"Unlike central government, councils can't borrow money to meet their day-to-day running costs.

"Instead, council borrowing is used to meet the cost of long-term investments, such as key infrastructure projects including new schools and transport links, which ensure taxpayers are able to continue benefiting from high quality services."

A CIPFA (Chartered Institute of Public Finance and Accountancy) spokesman said: " The Taxpayers Alliance's own documents show that local authorities hold £274 billion of long-term assets against their long-term liabilities of £180 billion.

"To focus only on liabilities is unhelpful and doesn't show the whole picture of local government finance.

"In addition, the two main areas they have focused on for their liabilities figure are the Local Government Pension scheme, which is the only significant pension scheme in the public sector that is funded, a nd long-term borrowing by local government that can only be used for investment in capital assets, s o that every pound borrowed is put into asset such as a road, a home or a school.

"Much of this borrowing is also at a very low market rate through the Public Works Loans Board.

"We need an informed debate about the funding of local government which we hope will be assisted by the new independent commission into local government finance."

A Liverpool City Council spokesman said: "The figures are just a snapshot in time and do not reflect our ability to fund our commitments in the long term. If you remove the local government pension scheme, which we are legally obliged by the Government to provide, we have net assets of almost £1 billion.

"The pensions liability, which has fallen by £157 million over the last year, stretches over many years and does not include the contributions that scheme members and the council will make in future. There are very strict rules in place around council borrowing and we can only do it to invest in long-term infrastructure projects that benefit local residents, or generate a return."

Local Government Minister Brandon Lewis said: "Councils account for a quarter of all public spending so it is vital that the sector continues to play its part tackling the inherited budget deficit by making sensible savings and delivering value for money for the taxpayer while protecting frontline services.

"This Government has greatly improved transparency and accountability of councils so local people can hold them to account for the way their money is spent and what that it is delivering. It has also reformed the Local Government Pension Scheme so it remains fair and affordable to taxpayers.

"By law councils have to balance their budgets each year.

"The latest official figures show that councils are sitting on around £220 billion of assets, which can be sold or used to reduce their level of borrowing."