Ten of Swindon's 15 libraries will close unless community groups take them over, a council has warned.
Staff were told the move was needed because the council needed to cut £1.5m a year from its libraries budget.
The meeting was told a "core network" of five libraries would be within two miles of 91% of residents' homes.
If approved by the borough council's cabinet and scrutiny committee, the restructure would come into force in April.
Library staff will learn of their fate on 22 December.
Conservative councillor Mary Martin said a lack of government funding "necessitated" a consultation into "how local libraries are provided and what are the most important services for people".
The five libraries chosen to be in the "core network" are Central, North Swindon, West Swindon, Highworth, and Park.
The 10 other libraries would see opening hours reduced to 15 hours per week from 5 April and would probably be funded until 31 August.
But the mobile library service will be axed from the end of March.
Sarah Church, of Save Swindon's Libraries campaign group, said it was "dreadful news" for staff who would lose or have to reapply for their jobs.
She added the move left "a lot of questions" and she was concerned for library users "in an area where they may not be a branch library next year".
Expressions of interest to run a community library need to be made before the end of January and a one-off fund of up to £500,000 will be available to fund the transition.