NEW BEDFORD — St. Luke's Hospital has filed a complaint against the Massachusetts Nurses Association, alleging voter fraud in the November 29 election by nurses to unionize.

Management at St. Luke's filed the complaint Thursday with the National Labor Relations Board, claiming that someone in the election voted used another voter's identity, preventing that voter from casting a legitimate ballot and creating the appearance of fraud. The hospital says the action casts doubt on the validity of the election.

St. Luke's also accused the Massachusetts Nurses Association of distributing material prior to the election that misrepresented the intended votes of nurses, the level of support for a union, and the effect of signing union cards in attempts to sway voters.

Management is asking the NLRB to disqualify the election.

The NLRB will investigate the claims.