Hitting out at the party he joined at its founding in 1980, Singh said the BJP was no longer what its founders Atal Behari Vajpayee, LK Advani and Bhairon Singh Shekhawat envisioned and there was "total confusion" between values, norms and unacceptable short cuts.
"A party that cannot afford its most loyal adherents even the very basic courtesies, puts petty whims of individuals before the greater good of the people has certainly lost its vision and frittered away its virtues for temporary political gains. To what end, only time will tell," Singh said in a statement.
The BJP had on Saturday expelled Singh for six years for contesting as an independent against party's official nominee Col Sonaram Choudhary from Barmer parliamentary constituency in Rajasthan.
Defending his decision to contest against "a Congress defector with questionable public record", Singh said the election in the segment exemplified how the values which the BJP stood for were being destroyed under the garb of "party discipline".
"This election in Barmer-Jaisalmer constituency very sadly exemplifies how these values are being perverted, indeed almost destroyed under the false pretense of party discipline, commitment to individuals rather than issues and principles, depressingly blatant disguising of facts and total confusion between values, norms and unacceptable short cuts."
Singh said he was "deeply saddened" over his expulsion but defended his decision to contest from Barmer, contending that the Congress candidate was chosen over him on considerations of caste and not on loyalty which he personally stood for.
"Because this decision lacks transparency, honesty and courtesy of appropriate communication, I am obliged to question it," Singh said, adding he would have supported any committed BJP member as a candidate from Barmer.
BJP president Rajnath Singh had said there were certain "political compulsions" that had led to the decision of not giving Jaswant Singh ticket from Barmer.
The state unit led by Vasundhara Raje had wanted Chaudhary to be fielded to rope in Jat votes.
"The party selected a candidate with a questionable public record who barely a day earlier had quit the Congress. To cover this decision, the party cast doubts over my
winnability and discredited my record be it over Ashok Gehlot in 1989 or twice in Chhittorgarh or most recently in Darjeeling. The party cited caste equation the defector belongs to but I don't subscribe to any caste and never have," Singh said, adding he needed to put the Barmer election in perspective.
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