No form of harrassment here except that they are very likely trying to do what is called "force a quit," and that's not illegal. You cannot sue, complain to the labor board or the bureau fo fairness, etc. The only thing to do is be looking very hard for another job. It's probably a better idea not to quit as long as you're getting 10 hours at your same job.
It may be reasonable to try to work with the company if they give you only 10 hours at the same job you have had, going ahead and filing for your unemployment while still working due to the reduction in hours. As I said, I strongly suspect that once you file for unemployment still working, this will be followed by another move on their part. If it's "hit the road, you're outta here!" take it and go quickly and quietly. As I said, unemployment is the only recourse if you are approved for it. Pursue your claim that you have already opened, now a dismissal instead of a reduction of hours.
Do not ever think it's better to quit than be fired, so that if they say you're being fired, don't announce, "You so and so's can't fire me, I quit!!" That does not "look better on your reference" or give you any leverage at all in unemployment, because it would probably be determined to be a quit by your choice. When that happens, the burden of proof that you had a valid job related reason to quit is on the claimant's plate. If you've been fired, the burden of proof to keep you from drawing unemployment is the job of the employer, who must have a good job related misconduct reason to fire. This just can't be something like the boss didn't like me. They can legally fire you for this reason, but if they don't have a documented evidence of some misconduct, they can't keep you from receiving unemployment.
But if they change your job location, slash your pay rate, or change your job description dramatically ( you used to be a design engineer, they are now giving you 10 hours a week as a machine operator) then I reiterate my advice not accept or to even work a minute of the newly structured job if you're going to find it too unacceptable and quit before you have another job.
Yes it is a chance that you will quit the job and not be approved for benefits. But for general unemployment purposes, acceptance of the new job, transfer, etc. is considered a (non binding, unstated)contract, and when you quit it, they'll find less reason to see it for you because you knew what the conditions were when you accepted it.