Gadkari also demanded that Prime Minister Manmohan Singh take moral responsibility for failing to prevent the 2G spectrum and other scams and resign.
"The Prime Minister is morally responsible as under his leadership so many scams are taking place...There are several instances where the PM could have prevented it but he has not been successful in doing so. He should take moral responsibility and resign in the interest of the country," Gadkari told reporters here.
Strongly denying charges that he had any business relationship with Radia, Gadkari said: "This is cent per cent lie. I have not even seen Nira Radia face-to-face. She has never called me, neither have I called her. And there is no issue of meeting her or helping her."
Countering charges of having favoured Radia in a helicopter deal in Maharashtra, Gadkari said the Congress was behind these allegations as it wanted to divert attention from itself.
"The image of the Congress is getting tarnished day by day. So they have abandoned their wisdom and patience. And due to this they are sinking. So they are abusing others to besmirch their name. This is unfortunate for democracy," he said.
Gadkari insisted that all charges made against L K Advani and him are "baseless" and challenged that if Rao Dheeraj Singh had the courage, he should bring out all the facts.
He was responding to charges levelled by Rao Dheeraj Singh, a former associate of Radia, that levelled allegations against senior Advani, Gadkari and general secretary Ananth Kumar of favouring the corporate lobbyist.
"I feel Congress should clear its name which is getting tarnished in the wake of new facts coming to light about Commonwealth Games and 2-G Spectrum scam. They cannot clear their name by accusing others," he said.
"When the time comes we will even take legal action against them. He (Rao Dheeraj Singh) is a criminal. Has been in jail. There are several cases against him."