Once the tenancy expires, the tenancy continues on a month-to-month basis. Landlord has the right to negotiate new terms for continuation of rental. If you don't agree, you have the right to be given notice of one month to vacate the premises. So in this case, either you agree to the new terms or you move out. Remember that during the one month notice period, you still pay the old rental and not the new one. Landlord has no right to impose new rental without your agreement.