A cursory reading of the text of the Bill (described as the Truth in Employment Act of 2011) suggests that employers would be entitled not only to refuse to hire a "salt”, but also to terminate a "salt" after discovering their undercover plot.
One suspects that this is "red meat" for the employer lobby. One gets a flavour for the underlying sentiment from the statement of purpose of the bill: "to alleviate pressure on employers to hire individuals who seek or gain employment in order to disrupt the workplace of the employer or otherwise inflict economic harm designed to put the employer out of business.” Ahem. In Ontario, these sorts of sentiments about unions are not expressed in polite company, although that may be how many employers actually feel.
"Salting" is a fairly common organizing tactic in the construction industry in Ontario, but is less common (or more successfully stealthy) in the industrial, retail or service sectors. “Salting” is typically infuriating to employers who experience it, so it's easy to see the political value of legislation that allows employers to terminate the "salts" themselves.
However, because individuals seldom identify themselves as undercover union organizers either at the time of hiring, or during an organizing campaign itself, it's hard to see when the necessary preconditions would arise for either refusing to hire, or terminating, a union organizer.
On the contrary, it is easy to foresee terminations (or hiring refusals) based on the suspicion, without much or any evidence, that the person is a “salt”, followed by acrimonious litigation that culminates in the employer losing the case.
The bigger problem that "salting" poses from a "workplace democracy" perspective is that individuals who are essentially salaried employees of unions are entitled to participate in the process of selecting the union itself – and are not restricted to trying to persuade others to select the union. In other words, a "salt" gets to vote – meaning that one of the institutional parties in a typically adversarial process gets a say in the outcome. Arguably, this contradicts the concept of majority rule, which is enshrined in Canada's labour legislation as a governing principle.
The OLRB has decided not to be troubled by this issue, citing the understandable (and perhaps legally defensible) rationale that the definition of "employee" does not require it to determine an individual's motivations, or whether the individual has employment with another organization of the same time. One suspects that the OLRB is not keen to see its already complicated certification processes additionally burdened by litigation over whether an individual is a "salt" are not.
Ontario employers who oppose "salting" are more likely to achieve success in a practical sense by seeking amendments to legislation that would require participants in a union "vote" to have at least a few weeks or a month of employment before they get to count.
Thanks to Littler Mendelson for the summary.