Congress' known face on news channel debates and Supreme Court Advocate Brijesh Kalappa has resigned from the primary membership of the party, ending his 25-years long association.

In a letter to Congress president Sonia Gandhi, he said, in the recent past he has been finding himself 'lacking in passion', while his own performance has been 'listless and perfunctory'.

He is likely join the Arvind Kejriwal-led Aam Aadmi Party soon, sources close to him said.

In a letter dated May 30, thanking Sonia Gandhi for opportunities given to him, including his appointment as Legal Advisor to Government of Karnataka with rank of minister during the party's rule in the state, Kalappa thanked her for 'patronage'.

Pointing out that he has been representing the party on Hindi, English and Kannada channels since the United Progressive Alliance years in 2013- for almost a decade and has clocked 6,497 debates, he said, besides, the party has been regularly assigning political work to him which he has performed to the best of his satisfaction.

'Even at the worst of times for the Party in the aftermath of 2014 and 2019 debacles, I have never felt enervated and lacking in energy and enthusiasm. But, in the recent past I have been finding myself lacking in passion, while my own performance has been listless and perfunctory,' Kalappa said.

'It is under these circumstances that I am left with little option but to resign from the primary membership of the Indian National Congress and to end an association that began in 1997,' he added.

According to some party sources, he might have also been upset over not being considered as candidate for recent MLC and upcoming Rajya Sabha polls in the state.

During the 2018 Assembly election, Kalappa had expressed his displeasure on being denied the ticket to contest from Madikeri, in his home district of Kodagu.