Former President and the Congress veteran Pranab Mukherjee kicked controversy on Thursday when he described Keshav Baliram Hedgewar as a 'great son of Mother India' as he visited the birthplace of the RSS founding Sarsanghachalak.

"Today I came here to pay my respect and homage to a great son of Mother India," Mukherjee wrote in a visitor's book at Hedgewar's birthplace ahead of his much-anticipated speech at the RSS headquarters here.

Those present included Subhash Chandra Bose's family members who have been invited as special guests, sources said.

Mukherjee, who was welcomed by the RSS chief Mohan Bhagwat, had to walk through narrow lanes to reach the house where Hedgewar was born and also removed his shoes before entering the place.

According to sources, this visit to pay tributes to Hedgewar was not part of Mukherjee's scheduled itinerary and an impromptu decision was taken by the former president to do so.

Mukherjee, who reached Nagpur last evening, has been invited by the RSS to address its Shiksha Varg and attend a parade by the Sangh workers on completion of the training camp.

It is an annual training camp, meant for swayamsevaks in their third year in the organisation. The RSS holds training camps for first, second and third-year swayamsewaks.

Mukherjee's decision to attend the RSS event has already triggered a major political slugfest with several Congress leaders criticising his decision.

Senior Congress leader Ahmed Patel today expressed his disapproval at former president Pranab Mukherjee visiting the RSS headquarters in Nagpur and said he did not expect this from him.

Mukherjee's daughter and Congress leader Sharmistha had on Wednesday said her father was giving the BJP and the Sangh a handle to plant false stories with his decision to speak at the RSS event.

His "speech will be forgotten" but the "visuals will remain", she said on Twitter. She also expressed the hope that the former president would realise how the BJP's "dirty tricks department" works and warned him of the consequences of attending such a meet.

Some Congress leaders, including Jairam Ramesh and C K Jaffar Sharief, also wrote to him, while a few leaders of the party, including Anand Sharma, personally visited him in a bid to dissuade him from going to Nagpur.

Congress senior spokesperson Anand Sharma took to Twitter to express his anguish soon after images of Mukherjee attending a function at the RSS headquarters in Nagpur appeared on television.

"The images of Pranab Da, veteran leader and ideologue at RSS Headquarters have anguished millions of Congress workers and all those who believed in pluralism, diversity and the foundational values of the Indian Republic," Sharma said.

"Dialogue can only be with those who are willing to listen, absorb and change. There is nothing to suggest that RSS has moved away from his core agenda as it seeks legitimacy," he added.