What protections are there for someone who is scheduled for surgery, which has been preapproved and the time off request has been acknowledged by the employer, but the employee is terminated prior to the surgery date? There's a whole subplot about validity of the employment agreement due to ambiguous terms that are being applied in favour of the employer and not the employee, an extended probationary period that was applied unilaterally and without consideration, and a couple other twists to complicate things, but in respect to having a medical leave approved but then the employee is terminated before the protected leave can begin, is there anything that protects the employee in that situtation?

I know the Ontario Teachers Unions have had some success with gauranteeing job security for teachers who become preganant but have not yet begun maternity leave, but that's Ontario, and union, and I am neither of those things.