The National Labor Relations Board threw out a vote by nurses to unionize at Cedars-Sinai Medical Center, Los Angeles, ruling that the California Nurses Association used unfair tactics that influenced the election.
The board's ruling, released Monday, found that anonymous threatening phone calls to an employee with known antiunion views was likely to have intimidated enough nurses to potentially change the outcome of the balloting, which the union won 696-627.
Chuck Idelson, a spokesman for the nurses association, said that the threats were "unfounded, unsubstantiated and uncorroborated allegations by one individual who was well known as the most antiunion official in the hospital."
The board found that agents of the union allegedly had told the man, who owned pets, that his kittens would look good in frying pans. On another occasion the man said he was told that his dogs would be stabbed or run over with cars.
Cedars-Sinai is one of the largest hospitals on the West Coast.
The nurses association represents about 58,000 nurses in California in 165 hospitals. In the last decade, nurses at hospitals throughout California have voted to join unions to seek better working conditions and pay.
Cedars-Sinai officials said that numerous nurses complained of misconduct by the union in the days before the election. The hospital's initial challenge to the election was denied by the board's regional office in March 2003. The hospital then appealed to the national office of the NLRB.