Sachin Pilot, whose open revolt in Rajasthan has left the Ashok Gehlot government near collapse, served a legal notice to Congress MLA Giriraj Singh Malinga on Tuesday over allegations that the sacked deputy chief minister offered him money to join the BJP.
Sources close to Mr Pilot confirmed the notice had been served - for false and malicious statements made by Mr Malinga to the press a day earlier.
On Monday Mr Malinga had told reporters in Jaipur: "I had a discussion with Sachin Pilot. He spoke to me and said how much do you want. He told me Rs 35 crore".
"This has been happening since December, it is nothing new. I told them I cannot do this," he said, adding that he had spoken to Mr Pilot "two-three times".
Mr Pilot, who is contesting his disqualification from the Rajasthan Assembly in the High Court, dismissed the allegation as "baseless and vexatious" and said he would take "strictest possible legal action".
"I am saddened but not surprised to be at the receiving end of such baseless and vexatious allegations being levelled against me. I am sure more such concocted allegations will be thrown at me to cause aspersions on my public image. But I shall be unfettered and remain firm in my beliefs," he declared.
The 42-year-old political leader, who was also removed as chief of the Rajasthan unit of the Congress, also suggested Mr Malinga had been "made to" level such allegations in order to stifle "legitimate concerns" raised against state leadership.
Giriraj Singh Malinga isn't the first Rajasthan Congress leader to accuse Sachin Pilot of conspiring to bribe MLAs on behalf of the BJP.
Chief Minister Gehlot has torn repeatedly into his former deputy since this crisis began, using words like "nikamma" and "nakaara" - variants of "worthless" - to describe him.
"He was conspiring for the past six months with the BJP's support. Nobody believed me when I used to say that a conspiracy is going on to topple the government. Nobody knew that a person with such an innocent face will do such thing," Mr Gehlot said.
Last week the Chief Minister said: "The former PCC chief was involved in dealings with BJP. I have proof of horse-trading".
Mr Pilot has repeatedly denied such allegations.
The feud between Team Gehlot and Team Pilot, never far from the surface, exploded after Mr Pilot was served a notice to answer questions over alleged attempts to destabilise the state government by bribing MLAs to join the BJP.
Mr Pilot and MLAs loyal to him were served a disqualification notice that they promptly took to court. They will find out on Friday whether they can, in fact, be disqualified.