The Supreme Court on Thursday issued a notice to Kerala Chief Minister Pinarayi Vijayan and others on a plea by the CBI challenging their discharge in an alleged corruption case involving three hydel power projects in the state.A bench of Justice N.V. Ramana and Justice S. Abdul Nazeer also stayed the trial of the case involving the award of contracts for the renovation of the three hydel power projects in Kerala.The Central Bureau of Investigation (CBI) had moved the top court challenging a Kerala High Court order discharging Vijayan and six others while allowing trial of the remaining three accused.The matter related to late 1990s when Vijayan was Power Minister in Kerala.Three accused, who were asked to face trial by the High Court too, had moved the top court challenging the High Court's verdict asking them to face trial.