Kathmandu. Former Nepali Congress President Purna Bahadur Khadka has congratulated Bhishma Raj Angdembe, who was elected as the leader of the parliamentary party, wishing him to make the responsibility of the leader of the main opposition party historic and significant.Angdembe, who became the leader of the party unanimously on Monday, visited Khadka's residence in Golfutar on Tuesday morning to meet Khadka. While congratulating Angdembe, who came to meet him, Khadka suggested strengthening the role in the overall parliamentary process.