Rival union contemplates legal challenge[Updated: 4 p.m.] CALIFORNIA -- Kaiser Permanente employees throughout the state voted to remain with the Service Employees International Union–United Healthcare Workers West instead of joining its rival offshoot, the National Union of Healthcare Workers, according to the National Labor Relations Board.

NUHW is considering a legal challenge to the election.

In voting from Sept. 13 through Oct. 4, a total of 18,290 votes were cast for SEIU, compared to 11,364 for NUHW, and 365 voted for no union at all.

A total of 1,222 ballots were voided, and 276 were challenged.

About 43,000 Kaiser employees took part in the vote, considered the largest since 1941, when the United Auto Workers organized at Ford Motor Co.

In Santa Rosa, approximately 1,250 employees were included; San Rafael, about 800; Napa, about 120; Fairfield, about 113; Vacaville, about 550; and about 1,900 in Vallejo.

With the win, SIEU is poised to retain $40 million in annual dues collected as well as its clout as the largest health care union on the West Coast.

But NUHW questioned the validity of election results and likely will file a challenge, according to a union spokeswoman.

The "outcome was not the overwhelming majority for NUHW caregivers could have won last year," the union said in a statement. Nineteen months ago, a majority of Kaiser workers had petitioned for a vote between the two unions.

NUHW alleges that SEIU "employed legal obstruction tactics" leading up to the election, but NUHW's appeal appears to be centered on its claim of collusion between Kaiser and SEIU.

An August federal lawsuit filed in San Francisco against Kaiser alleges the health care organization paid SEIU and its representatives and employees to "campaign against, vilify and denigrate" NUHW before the labor relations board held the election.

SEIU, the nation's largest union with 2.2 million members, called on NUHW to "respect workers' democratic decision and not file frivolous objections to the election."

NUHW has seven days from today to file objections but has not done so yet, a spokeswoman with the labor relations board said.

The fate of NUHW may hang in the balance, labor experts have said. With approximately 5,000 members throughout the state, the Kaiser elections would have been a significant boon to the new union or a severe blow to SEIU's health care presence in California.

NUHW formed in 2009 by former SEIU officials who were ousted under allegations of misuse of funds.

According to SEIU, NUHW's loss will have a "major influence" on any future elections and will "undermine" NUHW's appeal to other health care workers.

Kaiser said in a statement it believed the election was fair, the results were valid and Kaiser favored neither union.

"We will abide by the results of the election when the NLRB certifies the results," spokesman John Nelson said. "From the beginning of the disputes between SEIU-UHW and NUHW, we have been neutral and continue to be neutral."