Hello Nega,
Yes i was employeed when I applied for my wife's permit, your case is little bit different in a sense that your husband doesn't have job but he has valid Work Permit that's why I asked you to conform with CIC. I don't remeber exactly whether or not i submitted proof of employement when i was applying for my wife's work permit what i remember for sure is I applied her work permit based on my post graduate work permit but don't remember exactly if i submitted the employement letter. I would say its worth trying it, or what you can do is, arrange an offer letter than apply - it will make your case strong for sure.