Jethmalani also hit out at Gadkari for not being active on the issue of Presidential election in which the government is planning to field Finance Minister Pranab Mukherjee.
He cautioned the BJP, saying this would lead people to believe that the BJP has something to hide and hence has become an "impotent spectator" to the loot of our finances.
"Today, the nation has realised that its poverty and destitution are the result of widespread corruption and large-scale larceny of the national assets by mainly our present rulers. I am convinced and so is the nation by and large that half the present cabinet ought to be in jail," Jethmalani said in the letter dated May 23.
Addressing Gadkari as a colleague in the letter, the Rajya Sabha MP says he presumes the former would be concerned about the "sickness of our party" which registers no response to the even greater sickness of the ruling party.
"Our party leaders should be going round the country and proclaiming the stark truth. Our party workers must be holding demonstrations in every city and hamlet, in fact every nook and corner of the country. The nation wants feverish action," Jethmalani said.
He said that instead the country has got "tongue-tied leaders busy pulling down one another and creating an unmistakeable impression that they are suffering from some inexplicable inertia and paralysis".
Jethmalani has not spared Gadkari either in his letter and used caustic words against him too. "Your strange somnolence on the occasion of the imminent election of the nation's president is showing up our bankruptcy of talent that we cannot announce a name better than the current finance minister," Jethmalani said.
He warned Gadkari that the country is not wrong in concluding that "we too have skeletons in our cupboards which make us impotent spectators of the rape of our finances". "I am revolted by the incompetence of our leaders," Jethmalani said.
The eminent lawyer told Gadkari that he does not propose to lie low in the President's election when Congress Chief Sonia Gandhi is trying to "foist" Mukherjee on this "unfortunate nation".
Jethmalani ended his letter seeking an apology for his "anger" and its "uninhabited expression" but strikes a positive note, saying there is "some flicker of hope still left".
The Rajya Sabha MP from Rajasthan did not attend the BJP national executive meeting in Mumbai on May 24-25. He went abroad on May 23.
Read: Jethmalani's letter to Gadkari
