The BJP on Monday issued a show cause notice to Rajya Sabha MP Ram Jethmalani asking him to reply within 10 days as to why he should not be expelled from the party for six years.
BJP president Nitin Gadkari on Sunday suspended Jethmalani from the party and referred his case to the party's parliamentary board that meets on Monday.
The action came after Jethmalani said "nobody has the guts to take action against me".
Making the announcement, spokesperson Shahnawaz Hussain said the MP had disregarded the party line on Ranjit Sinha's appointment as the next CBI chief.
"The parliamentary board discussed the anti-party actions of Mr. Ram Jethmalani. The parliamentary party found appropriate the decision of party president Nitin Gadkari to suspend Jethmalani for his indiscipline and anti-party activities," BJP leader Ananth Kumar told reporters.
"We have also sent him a show cause notice to tell why he should not be expelled from the party for six years," he said.
Jethmalani had criticised the party's opposition to the appointment and also demanded Gadkari's resignation for alleged business irregularities.
Senior BJP leaders Sushma Swaraj and Arun Jaitley had opposed Sinha's appointment, saying the government should have waited as the report of the select committee on the lokpal bill had recommended that CBI directors be chosen through a collegium and not at the Centre's discretion.
Jethmalani implied the attack was instigated by a rival aspirant to the post and had welcomed the PM's move.
"We were concerned only and only with institutional reforms. Our suggestion wasn't person-centric," Jaitley said.
Jethmalani received support from party MP Shatrughan Sinha, who said, "The appointment was done in a fair and transparent manner."