WASHINGTON (MarketWatch) -- A bill aimed at stamping out wage discrimination was blocked Wednesday as too few senators voted to move forward with the legislation. The Paycheck Fairness Act needed 60 votes to move forward, and only captured 58. The bill would have amended the Equal Pay Act to limit the defense that employers can use to respond to charges of wage discrimination based on sex, among other actions. Supporters said stronger laws are needed to erase the persistent wage gap between men and women, while critics said the bill could hurt businesses and workers. According to the Labor Department, in 2009 the median weekly earnings of women who were full-time wage and salary workers were $657, compared with $819 for men. There's disagreement over how much of the gap is attributable to sexism.