3AE+WA tenancy—
(a)which is entered into on or after 1st April 1990 (otherwise than, where the dwelling-house had a rateable value on 31st March 1990, in pursuance of a contract made before 1st April 1990), and
(b)under which the rent payable for the time being is payable at a rate of, if the dwelling-house is in Greater London, £1,000 or less a year and, if it is elsewhere, £250 or less a year.