Read: Anger, apology over Shiv Sena MPs' Ramzan bullying
The incident rocked Parliament, where the UPA constituents demanded action against the Sena MP.
Congress and NCP have always used communalism and reservation for vote-bank politics and to "malign" the image of both BJP and Shiv Sena, he said.
Gadkari was addressing BJP activists at a function here in North Maharashtra on Friday evening.
Lashing out at the Congress and NCP, who were part of the UPA government at the Centre, he said the two parties were responsible for rising inequality, starvation deaths and unemployment in the country.
Read: Will ascertain facts first: Govt on Sena 'provocation'
He said the BJP-led NDA government was not against the farmers and maintained the Centre's proposed move to ban export of onion was a temporary step to control prices.
Earlier, the surface transport and shipping minister inaugurated a two-day seminar organised by the city branch of Builders Association of India.
Speaking on the occasion, Gadkari said the government was thinking of undertaking cement concretisation of national highways to increase their durability.
Read: Maharashtra Sadan incident an attempt to silence Shiv Sena's voice: Uddhav