The Congress has seen a series of exits in recent years.
Vikramaditya Singh, the son of former Governor Karan Singh, quit the Congress today saying the party is "disconnected with ground realities".
In a resignation posted on Twitter, the former Jammu and Kashmir legislative council member (MLC) said his position on critical issues "do not align" with that of the Congress.
"I hereby tender my resignation from the Indian National Congress. My position on critical issues vis-a-vis Jammu and Kashmir which reflect national interests do not align with that of the Congress Party. Congress remains disconnected with ground realities," Vikramaditya Singh wrote, sharing a screenshot of his letter to Sonia Gandhi.
In the letter, he said: "It is my belief that the Congress is unable to realise and reflect the sentiments and aspirations of the people of Jammu and Kashmir."
Mr Singh, the grandson of former royal Hari Singh, joined the Congress in 2018 and contested the 2019 national election from Uddhampur in Jammu and Kashmir. Before the Congress, he had been in Mehbooba Mufti's People's Democratic Party (PDP).
The Congress has seen a series of exits in recent years, alongside its defeats in election after election.
This year, the party lost former Union Ministers Ashwani Kumar, RPN Singh and Shatrughan Sinha.
Jyotiraditya Scindia's switch from the Congress to the BJP in 2020 started a virtual exodus from India's oldest party. Last year, Jitin Prasada took the same route.
With each exit, a group of 23 dissenters in the Congress - dubbed the G-23 - has flagged concerns about the drift in the party, its weakened structure and its inability to win elections, especially against the BJP.
The group had written to Sonia Gandhi, calling for a complete organisational and leadership revamp, months after Jyotiraditya Scindia quit the Congress.
Vikramaditya Singh was quoted as telling reporters that the Congress was unable to keep up with the times not just in Jammu and Kashmir but also at a national level. He said over the years, he had openly voiced views that were at odds with the party line.