Gandhi said immediately after his party's defeat in the April-May national elections that he would not continue as leader, but party barons had hoped to change his mind and Wednesday's official announcement still came as a surprise
Rahul Gandhi quit Wednesday as head of India's main opposition Congress party, taking the blame for a second-straight election humiliation by right-wing Hindu nationalist Prime Minister Narendra Modi.
"As president of the Congress party, I am responsible for the loss of the 2019 election," he said in a statement on his official Twitter account.
"Accountability is critical for the future growth of our party. It is for this reason that I have resigned as Congress president."
The 49-year-old, who was seeking to become the fourth member of the Nehru-Gandhi dynasty to become prime minister, had only been Congress president since December 2017.
Congress has dominated Indian politics since independence in 1948, but it has seen a spectacular collapse in support in the past decade.
Gandhi said immediately after his party's defeat in the April-May national elections that he would not continue as leader, but party barons had hoped to change his mind and Wednesday's official announcement still came as a surprise.
Congress won only 52 of the 543 seats in the lower house of parliament in the election. Modi's Bharatiya Janata Party (BJP) took 303 seats, increasing its majority as it won a second consecutive five-year term.
The BJP's huge victory stunned the opposition and political pundits who had predicted a reduced majority for Modi's party.
While saying he could not avoid his share of the blame, Gandhi launched a virulent attack on the BJP's tactics, hinting that the vote had not been free and fair and saying that the Indian press, judiciary and election commission had all been turned against the opposition.
It is an honour for me to serve the Congress Party, whose values and ideals have served as the lifeblood of our beautiful nation.— Rahul Gandhi (@RahulGandhi) July 3, 2019
I owe the country and my organisation a debt of tremendous gratitude and love.
Jai Hind 🇮🇳 pic.twitter.com/WWGYt5YG4V
"We didn't fight a political party in the 2019 election. Rather, we fought the entire machinery of the Indian state," he said.
Gandhi also accused the BJP of seeking to "destroy the fabric of our nation" and vowed to protect the country until his "last breath."
"I have no hatred or anger towards the BJP but every living cell in my body instinctively resists their idea of India," he said.
Critics accuse the BJP of stoking religious tensions and trying to undermine the country's secular credentials.
The BJP denies the accusations, insisting it believes in equality for all.
Around 80 percent of India's 1.3 billion population is Hindu, but it is also home to large numbers of Muslims, Christians and Buddhists.
The great-grandson, grandson and son of three past premiers of the world's biggest democracy, Gandhi had set out to rejuvenate the party after it lost to BJP in the 2014 election.
But he struggled to shed his image as a privileged, dynastic scion.
He even lost his constituency in Amethi, Uttar Pradesh, that had been a family bastion for decades. He was allowed to contest a second seat, however, and won in southern India.
Gandhi's efforts at rebuilding the so-called Grand Old Party also seemed to flounder with the senior members refusing to yield space to the younger generation. Media reports said party baron, 90-year-old Motilal Vora, would become interim chief.
"Rebuilding the party requires hard decisions and numerous people will have to be made accountable for the failure of 2019," Gandhi said.
"It would be unjust to hold others accountable but ignore my own responsibility," he added.
Analysts said Gandhi's resignation was likely to throw the party into fresh turmoil.
"Rahul Gandhi's resignation is an important point, but the bigger thing is what comes after this," Manisha Priyam, an independent political analyst, told AFP.
"Is it going to be a substitute who is going to be placed as the president?" she said indicating that making a Gandhi family pawn as new leader would not end its troubles.
Rahul Gandhi's mother, Italian-born Sonia, remains party chairperson. His sister Priyanka also took an increased role in this year's election.