Emergency excise power permits immediate temporary increases in duty rates subject to subsequent parliamentary approval and potential modification. Emergency power authorises the Central Government to amend the Fourth Schedule by notification to increase excise duty on specified goods where immediate action is necessary, substituting nil rates with rates not exceeding fifty percent ad valorem or otherwise doubling existing rates, with 'form or method' covering valuation and other measures; such notifications must be laid before Parliament and are subject to parliamentary approval, modification, annulment, and may be rescinded by the Government.