I suppose it is defamation. After all the Congress never claimed scams to be a necessity, and it is a false claim made about them on official stationery. But it is hardly a secret that in India, the line between defamation and educated view is one of class, rather than rule of law. India firmly believes in the concept of “jo hain naam wala wohin to badnaam hain”, which means only powerful people get defamed, apparently, because look what I found.
As per UPA, eating money (2G, Coal scam) is a necessity and eating food in an AC restaurant is luxury.