Calcutta: A Calcutta High Court lawyer has challenged a decision by a seven-judge collegium of the court to confer the "senior" designation on 170 advocates, questioning the "sudden rise" in the number and claiming the list had many "undeserving" candidates.

"Last time, in 2014, 33 advocates were elevated to the status of senior advocates. The elevation happened after a gap of eight years. The sudden rise in the number this time, and that too just after four years, has come as a surprise," Ramaprasad Sarkar said in his petition likely to be heard next week.

The elevations have also caused heartburn among lawyers and one of them, a former public prosecutor at the court, has written to Chief Justice Jyotirmay Bhattacharya protesting the "unprecedented" decision.

"Senior advocates can be identified by their gowns, which have longer sleeves than those worn by others and have rectangular flaps attached to their shoulders. They get higher respect in the Bar and the tag allows them to raise fees," said a high court source.

Senior lawyers get a preference when a three-judge collegium of the court sends to the Supreme Court the names of advocates to be considered as judges.

Before the new list was published last week, around 550 of the 10,000 lawyers were senior advocates at the court.

The collegium grants the status to some lawyers from time to time.

In his plea, Sarkar has said rules on conferring the status, laid down under the Advocates Act, 1961, were not observed this time and demanded a revision.

Calcutta High Court had in May 1997 laid down two primary conditions for selection as senior advocate by a special committee comprising seven judges - the person should be more than 40 years old, and should have been in the profession for 15 years.

Sarkar has claimed that the names of many lawyers who did not deserve the status figure in the latest list.

Debasish Roy, the former public prosecutor and advocate, has raised similar objections in his 50-page letter to Chief Justice Bhattacharya, contending that several deserving candidates could not make it to the list of seniors this time.

Asked about his case, Sarkar said: "Most members of the Calcutta High Court Bar Association are condemning the incident. In the process, the image of the oldest high court in the country has been tarnished. Many of my colleagues inspired me to lodge the case."