Glasgow City Council has been warned that home care services could be hit when an equal pay dispute is settled.
Officials are concerned that many long-serving staff will use the lump sum payments as an opportunity to move on.
About 78% of the 2,677 home carers are in line to receive money.
The council's chief social work officer has warned that up to 40% of staff could quit their posts after receiving payouts. They plan to recruit 400 new staff to fill the vacant posts.
In 2006, the council evaluated roles to ensure men and women received equal pay for jobs of the same value. Campaigners claimed traditionally female-dominated roles were paid up to £3 an hour less.
In a report submitted to Glasgow City's Integration Joint Board, Susanne Millar, Glasgow City Council's chief social work officer, warned officials that following the settlement pay out she anticipates up to 80% of staff in supervisory roles may hand in their notice.
Officials fear that staff - many of whom have had long careers with the council - may choose to leave or retire from the service in the coming months after receiving their settlement.
However, they stress that it will depend on what that settlement figure is.
Ms Millar's report states: "It is anticipated that between 18 - 40% of our home care staff may choose to leave.
"Furthermore, it is predicted that 50-80% of staff in supervisory roles who are key to the day to day planning of work, assessment and supervision of front line staff may choose to leave.
"This potential loss of staff, when considering the shift patterns and hours worked of those who may leave translates to a 38-40% loss of capacity in service."
She adds that plans are in place to recruit 400 new home carers to mitigate the potential loss of capacity, and to offer staff who want to stay different roles or working hours to maximise retention.
Over 10,000 people use the home care service every year, with carers delivering 87,000 visits a week.
The average age of a service user is 81 and they typically receive of 9.5 hours of home care every week.
Ms Millar's report is due to be presented to the Glasgow Health and Social Care Partnership on 27 March.
A spokesman for the council said: "We are currently understanding and planning for a potential loss of capacity in service provision as a result of the settlement of equal pay claims.
"We have an operational team looking at how we can mitigate against this situation and adapt the way we operate and deliver services, to lessen the impact.
"The precise effect on the service is uncertain at this stage but it is clearly prudent to prepare for what may lie ahead."
What are the roots of the dispute?
The problems arose from an earlier attempt to eliminate gender pay inequality. In 2006, Glasgow City Council adopted a job evaluation scheme with the aim of ensuring that men and women received equal pay for jobs of the same value.
While most local authorities adopted the "red book" scheme, Glasgow opted for a bespoke solution called the Workforce Pay and Benefits Review (WPBR) scheme.
There are two main problems with this:
- It included a three-year payment protection arrangement for men who lost out on bonuses as a result of the changes - but the provision was not extended to women.
- The design of the WPBR scheme itself. Staff contracted for more than 37 hours, for instance, qualified for extra payments. While women made up 70% of the council workforce, the vast majority worked fewer than 35 hours.
Campaigners say workers in traditionally female-dominated roles such as home care or catering were paid up to £3 an hour less than those in male-dominated jobs such as refuse workers or grave diggers.
In 2017, two judgements at the Court of Session ruled that both the payment protection scheme and the WPBR discriminated against women workers.
Thousands of council workers went on strike over the issue in October 2018.
In January, the council and unions reached an agreement in principle on a package of payments to resolve unequal pay claims.
It is likely the payments will total more than £500m and payments will be paid from April this year.
The following month, the council approved plans to finance the settlement by selling off major venues to an arm's length body and leasing them back.
The proposal involves transferring ownership of prominent buildings such as the Riverside Museum and the Emirates arena to a council-owned body.
It will take out long-term loans against the value of the venues.
They will then be rented back to the council with the cost of the lease designed to meet the loan repayments.