Explanation:

The minimum number of judges who are to sit for the  purpose of hearing any reference under Article 143 shall be five. If at any time it appears to the President that a question of law or fact has arisen, or is likely to arise, which is of    such a nature and of such public importance that it is expedient to obtain the opinion of the Supreme Court upon   it, he may refer the question to that Court for consideration and the Court may, after such hearing as it thinks fit, report  to the President its opinion thereon.