Hundreds of local authority staff are facing cuts to their pay in a savings drive.
Staff at North Devon Council have been asked to consider working fewer hours, having an unpaid holiday or taking redundancy.
A letter from the council's chief executive Mike Mansell was sent to about 470 staff last week.
In the letter, Mr Mansell said the authority had done "fantastically well" in saving close to £2 million over the past three years.
However, he warned that a similar sum must be saved in the coming three years and said compulsory redundancies could not be ruled out.
In the letter, Mr Mansell said: "North Devon Council has tried to avoid or at least mitigate against the amount of job losses by cutting back on other things such as the lease car scheme and mobile phones."
He added: "Unfortunately compulsory redundancies cannot be ruled out, however the council will do its utmost to avoid this."
Helen Willis, regional manager of the Unison union, said its members could not afford any further pay cuts.
She said: "Staff in North Devon Council have already been hit by a pay freeze for several years now meaning in real terms their pay has dropped by over 10%.
"Workloads have been increasing and of course many of the efficiencies already made have simply added pressure to frontline staff by reducing the support they have.
"These further proposed changes would mean that our members who are already struggling to pay their housing, heating and living costs are going to end up even further out of pocket. For many even if they keep their job this will be the final straw."
She added: "Research shows that many councils could make considerable efficiency savings through more effective procurement processes. Despite this, yet again we see the reality: frontline staff delivering absolutely crucial public services are the ones expected to take the hit."
She said that Unison would be "urgently seeking" to meet with the senior management team about the cuts. Staff have been asked to consider a number of ways they could change their working arrangements. Options include a reduction in the number of hours they work, unpaid leave for a fixed period, early retirement on the grounds of efficiency, voluntary redundancy, or exploring other opportunities.
They have been given until November 23 to apply to change their working arrangements.
The council's senior management team will then consider the applications in December.
A council spokesman said: "There is nothing unusual about this letter. It is the third time we have sent it out to staff and it usually goes out at this time of year. Each time it has gone out we have made significant savings from voluntary arrangements."