PRASUN ROY vs CALCUTTA METROPOLITAN DEVELOPMENTAUTHORITY & ANR.

The Supreme Court held that under Section 20 of the Arbitration Act, 1940, a party's long participation and acquiescence in arbitration proceedings precludes them from later contesting the jurisdiction of the arbitrator. The Court emphasized the principles of waiver and estoppel, stating that a party cannot simultaneously accept the proceedings and later challenge them. The appeal was allowed, affirming the validity of the arbitrator's appointment despite the respondent's challenge after extensive participation in the arbitration process.