Article 39(d) directs the State to secure equal pay for equal work. The Supreme Court first held this DPSP enforceable through Articles 14 and 16 in:

1. In Randhir Singh, the Supreme Court held that the principle of 'equal pay for equal work', though enshrined as a DPSP in Article 39(d), is enforceable as a Fundamental Right through Articles 14 and 16 read with the Preamble. 2. Mackinnon Mackenzie (1987) reinforced this for women employees under the Equal Remuneration Act, 1976. 3. Nargesh Meerza addressed discriminatory air-hostess service conditions but did not articulate the equal-pay doctrine first. 4. Hence Randhir Singh is the seminal authority. _Source: Constitution of India (Bare Act, updated to 105th Amendment Act 2021), Govt. of India Legislative Dept., Randhir Singh v. Union of India, AIR 1982 SC 879_