He also alleged that the BJP-led central government was "hell-bent on destroying" the elected Delhi government and added that the people of the five poll-bound states -- Punjab, Goa, Manipur, Uttar Pradesh and Uttarakhand -- will "teach the saffron party a lesson".
Referring to Kumar's letter, Sisodia claimed that his case was an indication that Prime Minister Narendra Modi and BJP chief Amit Shah were "afraid" of the AAP government in Delhi.
In a letter to the Delhi Chief Secretary yesterday, Kumar sought voluntary retirement from service and accused the CBI of "putting pressure" on him to implicate Kejriwal and beating up dozens of people during its probe into a graft case, charges rejected by the probe agency.