Congress leader Sam Pitroda said party chief Rahul Gandhi has experienced the trauma of terrorism and those questioning him in the matter should feel ashamed.
The remarks come at a time when Prime Minister Narendra Modi and other BJP leaders had often attacked the Congress president on the issue of terrorism and national security in the run up to Lok Sabha elections.
In an interview to PTI, Pitroda said Rahul Gandhi lost his grandmother (Indira Gandhi) and father (Rajiv Gandhi) to terrorism and that the leader understands the trauma and suffering associated with it.
He said those doubting Rahul Gandhi's nationalism should be ashamed of themselves.
Referring to senior BJP leader LK Advani's recent remarks in a blog post, the chief of Indian Overseas Congress said BJP leaders must learn from the veteran leader.
"I disagree with Advani on many issues, but respect him as a person. BJP leaders must learn from Advani who has advised against excess self-promotion and calling people with different political views as 'anti-national'," Pitroda said.
"Who has given BJP leaders the right to declare others as traitors?" he said.
On being asked about Congress' prospects in this election, the senior party leader said, "The elections may throw many surprises this time. Voters should remember that their votes can make or mar the country's future."
The long-time Gandhi family advisor said Narendra Modi and Rahul Gandhi are two different personalities.
One leader (Modi) has a manufactured image, while the other (Rahul) is an honest young leader who understands people's problems and has overcome many challenges, he said.
"Rahul belongs to a party which fought for the independence of the country. But what has been the contribution of the other leader's party in the freedom struggle?" Pitroda said.
When asked about the difference between the leadership of Rajiv Gandhi and Rahul Gandhi, the Congress leader said both the leaders belong to different times.
"Rajiv Gandhi had a huge mandate. But Rahul had to rise from the bottom. He has faced a lot of criticism and personal attacks. And yet, he rose and is ready to lead the country today," Pitroda claimed.
Raising questions on the use of electronic voting machines (EVMs) during elections, he said at least 50 per cent of EVM results should be matched with Voter Verifiable Paper Audit Trails (VVPATs).