Throughout any period which, by virtue of paragraph 17 or paragraph 18(2) above, falls to be disregarded for the purpose of determining whether the condition in paragraph 10(1)(c) is fulfilled with respect to a tenancy, no order shall be made for possession of the dwelling-house subject to that tenancy, other than an order which might be made if that tenancy were or, as the case may be, had been an assured tenancy.