"In politics there are two kinds of opposition. One the real opposition and the other the opposition from within, the opposition from your own people," Sinha said in an interview to television channel CNN-IBN.
The actor-MP asserted that he was willing to take on detractors within his own party. "But I would like to say when the going gets tough, the tough get going. I will take all kinds of opposition head on and will have the last laugh."
Sinha, who was a minister during the BJP-led National Democratic Alliance (NDA) government, described Gadkari as a "younger brother".
"Mr Gadkari is a nice person - he is like a younger brother. Whatever differences we have will be resolved. When I meet him the next time something positive and something light would come out. These are differences within the family and they will be resolved and sorted out."
On the issue of not being given any post in the new BJP team, he said: "It is a fact that I have not got any post but I'm a man with self-respect and I have not got any post because I have never sought one."
Asked to comment on the BJP leadership, he was all praise for Sushma Swaraj, now the leader of opposition in the Lok Sabha.
"Among the active politicians within the BJP, Yashwant Sinnha is there, Arun Shourie is one of the most learned and, of course, Sushma Swaraj is very capable. She is the tallest leader."