Some of North East Lincolnshire's ten libraries could be closed as the council looks to make budget cuts.
Up to £500,000 is to be cut from North East Lincolnshire Council's library services by 2014/15.
Closures, reduced opening hours or transferring control to voluntary groups are options being considered.
The authority said a two-month public consultation would take place before a final decision was made.
The Labour-run council said the service had been making efficiency savings for several years but more needed to be done to "balance the books".
Councillor Mick Burnett, portfolio holder for tourism, leisure and culture, said: "We need to consider all options and most importantly we need to seek the views of the local community.
"We have a duty to provide a good quality library service, but the stark facts are that we can't afford to provide the same level of financial support for the libraries as we have done in the past."
The consultation runs until the end of January.