Hi Zulfiqar,
Your landlord cannot unilaterally remove services that you have. So if you have a parking spot for your unit, they aren't allowed to just take it away.
But you said this was the "visitor" parking... if your lease states that you have access to visitor parking for your guests, then they cannot do this, but I suspect that this isn't listed in your lease, in which case it's unclear.
If I were you I would telephone (or e-mail) the experts at the FMTA: The Federation of Metro Tenant Associations (FMTA) is a renter advocacy organisation here in Toronto that has many experts who can answer your questions either by telephone (416-921-9494), postal-mail, or e-mail (hotline@torontotenants.org).
Let us know what they say.
- Rick