Protective customs duties can be altered by notification and require parliamentary approval; increases, reductions, and rescission are permitted. Where a duty in the First Schedule is characterised as protective, it is effective only up to the date specified in that Schedule. The Central Government may, after inquiry, increase or reduce such protective duty by notification if it is satisfied the duty is ineffective or excessive and immediate action is necessary. An increase by notification must be laid before Parliament and is subject to parliamentary approval or modification, and any such notification may later be rescinded by notification.