Veteran leader Shankersinh Vaghela, who quit the Congress two days ago, resigned as Leader of Opposition in the Gujarat Assembly on Sunday.
He sent his resignation letter to Congress president Sonia Gandhi.
In his letter shared with the media, the former chief minister alleged that he was forced to take this 'tough decision' as some Congress leaders were conspiring against him ahead of the assembly polls, expected to be held in Gujarat in December.
On July 21, Vaghela on his 77th birthday had announced to quit the Congress at a public gathering of his supporters.
Vaghela, who joined the Congress in 1998, claimed that just like some Congress leaders conspired against him in 2009, when he lost Godhara (Panchmahal) Lok Sabha seat, similar attempts were made to oust him from the party in recent times.
'As I can see right now that once again history is repeating itself, as a well-planned conspiracy within the party is at work for ousting me during the forthcoming elections. Hence, I strongly feel that I should not remain in the party at the cost of my dignity and self-respect,' he said in the letter.
Vaghela said since he has also decided to resign as the sitting Congress MLA of Kapadwanj seat, he will submit his resignation to the Gujarat Assembly speaker in the coming days.
In his 'farewell' speech on Friday, Vaghela announced he would resign as MLA on August 15, after the Rajya Sabha polls, to be held on August 8.
In the letter, Vaghela thanked Gandhi for making him Union minister in the United Progressive Alliance-1 government.
Venting his anger on the Congress, Vaghela claimed he was left with no other option but to resign as his suggestions for the upcoming Assembly polls were not accepted.
On Friday, the former Rashtriya Swayamsevak Sangh leader, who left the Bharatiya Janata Party 20 years ago and later joined the Congress, also announced that he will not join any political party, not even the BJP.
Though he refused to divulge details about his future plans, he maintained he is not retiring from public life.
Vaghela had been at loggerheads with the Congress leadership for quite some time over his demand that he be projected as the chief ministerial face in the poll-bound state.
He had been contending that if he was projected as the CM candidate in the polls, the party would be able to take on the BJP effectively in Prime Minister Narendra Modi's home state.
Vaghela's move comes close on the heels of the Congress failing to muster its entire strength in the presidential election held on July 17.
Congress-backed candidate Meira Kumar could garner only 49 votes against the party's strength of 57 in the state assembly.
IMAGE: Shankarsinh Vaghela at a public meeting of his supporters in Gandhinagar. Photograph: PTI Photo