S. MURALIDHAR, J.

1. The Union of India has in this appeal challenged an order dated 23rd January 2019 passed by the leaned Single Judge allowing the writ petition filed by the Respondent and declaring that he is for the purposes of calculating the "qualifying service" for pension, entitled to add 10 years of his practice at the bar along with his service as Member (Judicial) of the Central Administrative Tribunal ("CAT") as in the case of those Members (Judicial) of CAT appointed after 19th February 2007.

2. The facts in brief are that the Petitioner was enrolled as an Advocate with the Bar Council of Delhi on 12th October 1984. He was appointed Member (Judicial) in the CAT, Principal Bench, on 12th October 2000. At the end of the Respondent's initial term of appointment as Member (Judicial) for 5 years, he was granted an extension by another term of 5 years. He demitted office on 10th December 2010.

3. The Respondent's appointment as such was governed by the CAT (Salaries and Allowances and Conditions of Service of Members) Rules, 1985 ("1985 Rules"). The formula for pension on completion of 2 years of service was @ Rs.4716/- per annum for each completing year of service. Pension was fixed as per Part III of the First Schedule to the High Court Judges Conditions of Services Act, 1954 ("HCJ Act"). The pension formula was amended on 22nd July 2009 by replacement of per annum amount for pension as Rs.14532/- with effect from 1st January 2006. The pension of the Respondent as per the amended formula of 2009 was fixed at Rs.12,110/- per annum. This was based only on his ten years' service as Member (Judicial) without adding a further 10 years of practice at the bar to the period of "qualifying service" for pension.

4. The Young Lawyers Association (Registered) filed a public interest litigation ("PIL") in this Court inter alia seeking a mandamus to the Govt. of NCT of Delhi ("GNCTD") that the actual period of practice at the bar, subject to a maximum 15 years, should be added to the total qualifying service while computing the pension and other retiral benefits in the case of direct recruits in the Delhi Higher Judicial Service. This Court in All India Young Lawyers Association (Registered) v. GNCTD, (2006) 128 DLT 29 allowed the prayer and directed that Rule 26 (B) should be inserted in the Delhi Higher Judicial Services Rules, 1970 and weightage of 15 years of practice or such other number of years of practice at the bar, whichever is less, should be given to the direct recruits while computing their pension and other retiral benefits.

5. The said judgment was appealed against in the Supreme Court. In Government of NCT of Delhi v. All India Young Lawyers Association (Registered), (2009) 14 SCC 49 the Supreme Court partly allowed the appeal and deemed it appropriate to direct that "10 years practice at the bar or such other number of years or whichever is less, should be added while computing pension and other retiral benefits in the case of a direct recruit through the DHJS". In order to be eligible for pension, a person should have completed at least 10 years as DHJS.

6. Meanwhile, in 2006, an amendment was carried out in the Administrative Tribunals Act, 1985 ("AT Act") by Administrative Tribunals (Amendment) Act 2006 with effect from 19th February 2007. Under Section 6 (2) (b) a person shall not be qualified for appointment as "a Judicial Member, unless he is or has qualified to be a Judge of a High Court or he has for at least two years held the post of a Secretary to the Government of India in the Department of Legal Affairs or the Legislative Department including Member- Secretary, Law Commission of India or held a post of Additional Secretary to the Government of India in the Department of Legal Affairs and Legislative Department at least for a period of five years." It is important to note that the qualification that the candidate "is or has qualified to be a Judge of a High Court" existed even prior to the amendmen