(1) Where, in respect of any goods, the Central Government is satisfied that the duty leviable thereon under section 3 should be increased and that circumstances exist which render it necessary to take immediate action, the Central Government may, by notification in the Official Gazette, amend the Fourth Schedule to substitute the rate of duty specified therein in respect of such goods in the following manner, namely :-

(a) in a case where the rate of duty as specified in the Fourth Schedule as in force immediately before the issue of such notification is nil, a rate of duty not exceeding fifty per cent. ad valorem expressed in any form or method;

(b) in any other case, a rate of duty which shall not be more than twice the rate of duty specified in respect of such goods in the Fourth Schedule as in force immediately before the issue of the said notification :

Provided that the Central Government shall not issue any notification under this sub-section for substituting the rate of duty in respect of any goods as specified by an earlier notification issued under this sub-section by that Government before such earlier notification has been approved with or without modifications under sub-section (2).

Explanation . - For the purposes of this sub-section, the term "form or method", in relation to a rate of duty of excise, means the basis, including valuation, weight, number, length, area, volume or any other measure, on which the duty may be levied.

(2) Every notification under sub-section (1) shall be laid before each House of Parliament, if it is in session, as soon as may be after the issue of the notification, and, if it is not in session, within seven days of its re-assembly, and the Central Government shall seek the approval of Parliament to the notification by a resolution moved within a period of fifteen days beginning with the day on which the notification is so laid before the House of the People and if Parliament makes any modification in the notification or directs that the notification should cease to have effect, the notification shall thereafter have effect only in such modified form or be of no effect, as the case may be, but without prejudice to the validity of anything previously done there under.

(3) Any notification issued under sub-section (1), including a notification approved or modified under sub-section (2), may be rescinded by the Central Government at any time by issuing notification in the Official Gazette.