Council chiefs on Orkney have been accused of launching “an attack” on hundreds of the authority’s lowest paid workers.
Staff have reacted furiously to “deeply offensive” plans to change the terms and conditions of their contracts.
And there is anger that voluntary redundancy packages are being offered only to better paid officials at the same time.
The move emerged as the local authority revealed it faces a potential funding gap of £9.5million over the next three years.
Cost-cutting plans include withholding the 1% public sector pay rise offer for next year, cutting shift allowances and overtime for frontline staff, and slashing the number of public holidays from 10 per year to just four.
Hundreds are believed to be impacted, primarily roads, transport, refuse and care workers.
GMB regional organiser Liz Gordon said it was particularly galling because the proposals had emerged at the same time that the council had agreed a “preferential voluntary redundancy scheme” for those at the other end of the pay scale.
She said that frontline workers would be excluded from the voluntary redundancy offer, which meant it would only apply to managers and senior administrators.
Ms Gordon said: “This is deeply offensive to any straight-thinking person that you can take from the lowest paid in the workforce while at the same time agreeing a preferential redundancy scheme.”
About 40 members turned out for a last-minute union meeting on the proposals on Thursday evening.
Ms Gordon said: “I can accept that the council has said these are potential savings options and it is not going to impose all the proposals, but they give a very clear direction of travel.”
It is understood that the plans will now be considered by the council’s human resources senior managers before being put to the members.
Ms Gordon said: “If the council passes them, I believe they will try to impose them, which is why we are fighting them now.
“We have made it very clear that we oppose any change to the terms and conditions for the lowest paid.
“Orkney Island Council has access to a great deal of reserves from the oil and wind industry, but it would rather take money from its lowest paid workers rather than looking at other ways of saving money.”
Orkney Islands Council chief executive Alistair Buchan said: “In common with other councils, we anticipate having significantly reduced government funding with which to provide services in the years ahead.
“There’s a number of unknowns at the moment, but potentially we may have to address a funding gap of around £9.5million over a three-year period from 2017 to 2020.”
He added that the council had to consider all areas where savings could be made, including staffing costs.
Mr Buchan said: “We’re having to look at our spend on overtime, shift allowances, standby, sleep-in and call-out payments because we currently spend around £2million on payments of this kind each year and any savings we can make will help reduce the need to cut jobs and services.
“This is of course a matter of concern for our staff and we are approaching it in a careful and planned way and would stress that we’re just considering options at the moment and no definite decisions have yet been taken.
“We are involving our recognised trade unions in discussions around these issues.”