Unison’s Scottish secretary, Matt Smith, urged delegates to vote for industrial action over what the union perceives to be an attack on local government pensions.

The row centres on plans to scrap an early retirement concession called the “rule of 85”, which allows council workers to retire from age 60 if their age and years of service add up to 85 or more.

The Government claims it is being forced to ditch the rule because of European legislation — a position the union wants to test.

Mr Smith told members, “We now need an overwhelming vote in favour of industrial action from our LGPS (local government pension scheme) members to show governments both north and south of the border the huge depth of resentment this is creating in loyal public servants.”

However, the LGA warned that a “detailed analysis” had discovered that retention of the rule of 85 would cost £6 billion over the next 15 years. This is based on the union demand for the rule to apply to all LGPS members in the scheme as of September 30.

LGA chairman Sir Sandy Bruce Lockhart said, “The council taxpayer simply cannot pay more. The changes to local government staff pensions are both needed and necessary.

“There must be a modern scheme that is affordable and viable. People are living longer and unless action is taken now the cost to individual council taxpayers and local government will continue to rise.

“The key aspect of these changes is to make sure the pension scheme does not cost the council tax payer any more money while at the same time making sure local government continues to be an attractive place to work in.

“The council taxpayer currently pays more than double that of the staff members in contributions into the pension scheme and this has to be addressed.”

Unison’s Dundee branch secretary Rory Malone said low-paid LGPS members were the only public sector staff not to have a guarantee to retain early retirement on an unreduced pension.

He added, “The LGPS is part of the contract that members accepted when they joined local government. They are angry that a unilateral attack on their pay and conditions is to be imposed despite there being little or no justification. We fully expect a large “yes” vote.”

Unison is balloting over 100,000 members across the public services in the UK, with the vote due to finish on March 10. Ballots are also under way in other unions with local government members.

The LGPS covers staff working for the police and fire services, colleges and some university staff, Scottish Water, the Scottish Environment Protection Agency and other central agencies and the community and voluntary sectors, as well as local authorities.