For every £5 in revenue raised by local authorities, more than £1 now goes to fund the retirement of their staff.

Overall, spending on local government pensions rose 13% last year to hit £4.6 billion, according to figures obtained by campaigning group the TaxPayers' Alliance.

The scale of the burden emerged as families braced themselves for another inflation-busting council tax increase of 3.9% - taking the average bill for a Band D home to £1,370.

Although the increase is expected to be the lowest for 14 years, the levy has still more than doubled over the past decade.

TaxPayers' Alliance chairman Andrew Allum warned that society's most vulnerable were being hurt by the over-generous provision for council staff.

The Local Government Pension Scheme (LGPS) is still linked to final salary, and allows many employees to retire early with full benefits.

"It's unacceptable that ordinary families and pensioners who struggle to pay inflated council tax bills see so much of their money spent on gold-plated council pensions that have all but disappeared in the wider economy," Mr Allum said.

"The problem is clearly getting worse and requires urgent attention. Councils should start correcting their own behaviour immediately, and the Government must face down union pressure and reform the outdated local government pensions scheme as soon as possible."

The researchers used freedom of information laws to obtain copies of annual accounts from 98% of councils in England and Wales.