Meaning of "substantial question of law" under Wealth Tax act explained

In Maharaja Amrinder Singh vs. CWT, the appellant is the wealth tax assessee and is subjected to payment of Wealth Tax under the Act. The case pertains to the Assessment Years 1981-82, 1982-83 and 1983-84. The issue involved in these three assessment years was decided by the Tribunal in favour of the appellant (assessee) which gave rise to filing of the appeals before the High Court by the Revenue under Section 27-A of the Act questioning therein the legality and correctness of the orders of  the Tribunal. 

The High Court allowed the appeals filed by the Revenue, which has given rise to filing of these appeals by way of special leave before this Court by the assessee.

The short question, which arose for consideration in these appeals, is whether the High Court was justified in allowing the appeals filed by the Revenue and thereby was justified in setting aside the orders passed by the Tribunal.

Having heard the learned counsel for the parties and on perusal of the record of the case, the Suprem Court decided that the High Court cannot proceed to hear a second appeal without formulating the substantial question of law involved in the appeal and if it does so it acts illegally and in abnegation or abdication of the duty case on Court. The existence of substantial question of law is the sine qua non for the exercise of the jurisdiction under the amended Section 100 of the Code of Civil Procedure which is the guiding principal to the Wealth Tax Act.