CPCC general secretary (in-charge) Girish Dewangan issued a show-cause notice to Rai, an MLA from Gunderdehi, yesterday.
MLA Rai had been making anti-party statements in the media which was indiscipline, the party spokesperson Mahendra Chhabra said in a statement.
The legislator had been asked to reply within seven days, he said.
Rai is believed to be a staunch supporter of the former Chief Minister Ajit Jogi who floated Chhattisgarh Janata Congress (J) after parting ways with Congress in June.
Rai has been making favourable remarks about Jogi ever since.