"Due notice" is notice fairly and reasonably calculated to acquaint the employee with the existence of work that is available. The Commission found in one case that a three-week phone notice was clearly sufficient to acquaint the employee with the existence of available work and was likewise reasonable. You received only 46 hours notice but you may nevertheless have difficulty collecting your UI benefits because, "to read an employee’s personal circumstances into the due notice requirement would destroy the uniformity and consistency needed to apply the statute in any rational manner", the Commission has ruled. The question for the UI judge to decide in your case is whether the 46 hour notice you received was typical by that employer and for that job.
The UI Act is also specifically addressed to cases in which an employee suspends employment by taking a leave of absence. The fact that a claimant's inability to work was involuntary does not make his leave involuntary. In other words, a claimant would be ineligible for UI benefits during a leave of absence initiated by the employee. Again, the issue would be whether you initiated the leave, or the employer initiated the leave by failing to give you sufficient notice in which case you would qualify for benefits.
Despite the hurdles discussed above, this is a claim you should appeal if you are initially denied benefits.