Some 84 jobs could be lost at Western Isles Council under the present round of proposed budget cuts.
Council leader Angus Campbell revealed the figure during a public consultation meeting.
Council union Unison has raised concerns the cuts face hitting important services for vulnerable groups.
The job loss figure could rise in the wider local economy from the knock-on impact of the savings drive.
For example, moving children in residential care into foster care risks a further 28 private sector posts.
A reduction in central government funding forces the council to propose a raft of cuts and savings to stave off an estimated £14 million blackhole for the next two years.
Flora Somerville, the branch chairperson of public sector union Unison, said: “Cutting jobs has a direct impact on councils’ ability to deliver high quality services to our local communities.
“Cuts to local services have a disproportionate impact on those with low incomes, the elderly, disabled and other vulnerable groups.
“Good quality services provided by local government must be properly funded.”
The council is poised to slash spending and implement cuts to shore up nearly two thirds of its deficit.
But £5 million is still to be found.
Even if a list of 29 proposed cuts were agreed, the council would be left with shortfalls of £1.5 million this year and £3.6 million in 2017, says a report.
However, the body has £5.4 million of uncommitted funds which could offset the shortfall in the short term.
But it still risks having a £3.6 million deficit in two years time.
Council leader Angus Campbell said: “Due to past financial management we are in a more fortunate position than some other local authorities in setting our budget.
“However having to find this level of savings on top of the savings made over the past few years is challenging to say the least.”
The council has a budget of around £111 million this year.