A proposal by King County Executive Dow Constantine on Thursday could postpone or eliminate a need for a regional jail in Bellevue.

Constantine proposed providing area cities with 150 beds in the King County Jail until 2020. The idea would take the pressure off Bellevue and other large cities including Seattle, Kirkland, Redmond and Shoreline to plan for a regional jail if the county facility becomes full.

Constantine’s proposal would need County Council approval.

Bellevue and partner cities were studying where to build a 640-bed, $110 million regional jail. Cities in South King County launched their own effort and are building a new jail in Des Moines.

One of the proposed sites for a regional jail here was on 116th Avenue Northeast between Northeast Fourth and Northeast Eighth streets.

King County earlier this month extended Bellevue’s contract for jail beds through 2016.

“By making the best use of space in our existing jails, we create the time to explore every option for meeting the region’s future need for jail bed beds,” Constantine said.

Constantine said his proposal is based on a decline in inmate population in King County, which frees up jail beds in the county’s facilities, and more contracting options becoming available to cities to meet their needs for jail beds for misdemeanor offenders. These options did not exist when Bellevue and other cities north and east of Seattle started planning for a regional municipal jail in 2008.