A second election may be scheduled for 43,500 Kaiser Permanente workers who have been swept up in a bitter rivalry between two unions.

An administrative law judge has recommended that the results of a fall 2010 mail-in ballot be set aside and another election held.

Kaiser workers had voted to stay with Service Employees International Union- United Healthcare Workers West instead of switching to a breakaway group, the National Union of Healthcare Workers, founded by longtime labor chief Sal Rosselli after he was ousted from SEIU.

It was a decisive victory for SEIU, with 18,290 votes, or 61 percent, in favor of remaining with the organization and 11,364, or 38 percent, supporting a switch to NUHW.

But after NUHW challenged the outcome, Administrative Law Judge Lana Parke concluded that Kaiser's decision to deny April 2010 pay raises to some NUHW-represented employees in Southern California, and SEIU's warning to Northern California employees that their pay raises could similarly be in jeopardy if they switched to NUHW, provided the grounds to recommend a new election.

Another judge ruled that Kaiser illegally withheld the Southern California pay raises. When SEIU argued that Kaiser may withhold raises if other workers switch to NUHW, that "tended to stoke unwarranted and coercive voter fears" that interfered with a free election, Parke concluded.

SEIU has until July 28 to appeal the administrative law judge's recommendation. The National Labor Relations Board will then decide whether to call a second election. Employees involved in the vote included respiratory therapists, dietitians, housekeepers, pharmacy technicians, clerical employees, radiology technicians and other workers.