The Chikkaballapura MLA tweeted: "Personally I am confused why the issue of EVM manipulation is being brought into conversation while talking about the exit poll results.
While Nagaraj made no clear announcement of taking back resignation, the same was affirmed by Shivakumar while speaking to media outside Nagaraj's residence.
The coalition government is on a shaky wicket with 16 MLAs -- 13 of the Congress and three of the Janata Dal-Secular -- resigning their assembly membership. Besides, two independent legislators, who were made ministers recently to provide stability, have quit the ministry and withdrawn support.
Within a week of assuming power, the Congress government in Karnataka has expanded its cabinet on Saturday, filling all posts.
Nagaraj reached Mumbai accompanied by Karnataka BJP president B S Yeddyurappa's personal assistant Santosh and BJP MLA R Ashok.
The BJP will need to win at least six seats to remain in power.
The BJP won 12 of 15 seats on which bypolls were held. Congress could win only two.