Special Leave Petition to challenge stays on GST tax collection when substantial legal question or manifest injustice arises. Where a High Court has stayed collection or recovery of GST, a Special Leave Petition (SLP) should be considered and pursued when the levy is questioned or a substantial question of law of public importance or manifest injustice arises; affected units must prepare a self-contained proposal after thorough examination of the impugned order and submit it promptly to Commissioner (Legal) for action to defend government revenue.