MARTINEZ -- A countywide sales tax measure is off the table -- at least for this year -- after a poll found lukewarm voter support and the Board of Supervisors determined that even a long campaign would not generate the required level of approval.

But the board, looking toward a possible sales tax hike within the next two years, kept alive its pursuit of state legislation that would waive the current 9.5 percent cap on sales tax rates. That cap would be exceeded in two Contra Costa cities -- El Cerrito and Moraga -- in the event of a half- or quarter-cent countywide sales tax increase, the range that the pollster, EMC Research, looked into. Assembly Bill 1324, sponsored by Assemblywoman Nancy Skinner, D-Berkeley, would create an exemption for the affected cities.

The idea for a sales tax hike emerged shortly after the failure May 6 of a parcel tax measure in the West Contra Costa Healthcare District that would have raised an estimated $20 million a year, enough to stanch an annual $18 million operating deficit and avert the closure of Doctors Medical Center San Pablo.

By the time the tax idea came before county supervisors June 3, its purpose had expanded to hiring extra sheriff's deputies, reopening closed fire stations, enhancing overall emergency response and bolstering libraries, in addition to funding health care. The broad scope, officials said, would have qualified it as a general tax, requiring only a simple majority of yes-votes, rather than a special tax that would have needed a two-thirds supermajority.

Tuesday's board vote to abandon pursuit of a November 2014 sales tax measure was 5-0. The vote to continue to pursue state legislation was 3-2, with Supervisors Candace Andersen and Mary Piepho dissenting. Earlier in the meeting, both had lamented the poll's $45,000 cost.

The poll, which logged 806 responses from throughout the county, found an initial 54 percent likely approval rate for a quarter-cent hike, with 41 percent opposed, and 5 percent undecided.

A half-cent hike met with an initial 49 percent likely approval rate, versus 44 percent rejection.

Support for the tax increased after respondents received positive information about potential projects and programs that would receive funding: up to 62 percent likely in favor of a quarter-cent hike and 54 percent for a half-cent hike. But voter support also was susceptible to negative statements, the poll found.