"I am not saying what happened in Parliament yesterday was the right thing... Definitely, all of us regret, all of us feel ashamed of what happened," he said.
Rajagopal was widely condemned for the incident, which saw him being suspended from Lok Sabha by Speaker Meira Kumar.
Appearing to have mellowed down a day after, he, however, defended his act and said he had used the pepper spray to defend one of his parliamentary colleagues, who was being "manhandled" by political opponents.
Some Lok Sabha members, "at the behest of the Congress leadership", had tried to "manhandle" MPs from Seemandhra, he said.
"I had to do something in self-defence. I did not want to use tactics like engaging in a fistfight... hence I used the spray when I saw a colleague from a different party being manhandled," he said.
Rajagopal had on Thursday demanded that the Congress MPs who had allegedly "pounced" on him and TDP member Venugopal Reddy also be suspended.
"I went to rescue Venugopal Reddy when he was targeted by Congress MPs while protesting in the Well of the House. (But) they started attacking me. So, I used the pepper spray in self defence," Rajagopal had said.
He said he always carries pepper spray as he was "under a great threat from these forces" -- a reference to Telangana statehood supporters.
Asked to react to the incident, Rajagopal had on Thursday said, "Congress talks about democracy" but is indulging in a blame game "without following any democratic practices".
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