After the election of 1994 Melkert was appointed as Minister of Social Affairs and Employment in the Cabinet Kok I taking office on 22 August 1994.

After the election of 1998 Melkert returned to the House of Representatives on 19 May 1998 and declined to serve in the new cabinet and was selected as Parliamentary leader on 13 July 1998.

Melkert continued to be active in politics and in December 2015 was nominated as a Member of the Council of State on 20 January 2016.

Melkert also became active in the private and public sectors as a corporate and non-profit director and served on several state commissions and councils on behalf of the government, and works as a trade association executive serving as Chairman of the Dutch Hospitals association since December 2018 and became a Member of the Social and Economic Council for the Industry and Employers confederation (VNO-NCW) in April 2019.

Adrianus Petrus Wilhelmus Melkert was born into a Roman Catholic middle-class family in Gouderak, a small village situated in the province of South Holland.

He graduated in 1981 and received the Dutch Society for International Relations prize for best Master's thesis of 1981, the subject of which dealt with the foreign policy of the Den Uyl cabinet.

Despite concerns regarding Melkert's policy of marginalising and isolating the Socialist Party, he was seen as a competent politician and was designated to succeed Prime Minister, Wim Kok, who officially retired as leader of the PvdA in 2001.

Melkert and Dijkstal were the front runners in the early stages of the campaign but the unexpected arrival of former Sociology professor Pim Fortuyn of the Livable Netherlands (LN) party and later the Pim Fortuyn List (LPF) party turned the polls.

Fortuyn shifted the election issues from Business as usual to Immigration and Integration policies, Healthcare reform and the state of the Public sector.

Steps were taken to redress the possibility of a negative, bureaucratic image and it was revealed that Melkert was an avid follower of Feyenoord football club and enjoyed culinary pursuits: a cookbook was published on his personal website.

In May 2006 Melkert revealed to politician-turned-television personality, Paul Rosenmöller, that perhaps by being too entrenched in the confines of the governmental tower, his demeanour had come across as somewhat patronising: something that did not appeal to the voter.

A few relatively minor riots erupted in The Hague where Melkert was at the time, urging him to make a quick departure from the city.

Melkert resigned as political leader on election night and was replaced by the former speaker of the House of Representatives, Jeltje van Nieuwenhoven.

He was a candidate to succeed Juan Somavía as Director-General of the International Labour Organization but lost to Guy Ryder.

Melkert opposed merger plans, arguing that the focus of GroenLinks on climate change would deter moderate voters.

He said that the PvdA should win back working-class people, and he has supported Rood Vooruit, an initiative founded in 2023 that has been critical of a merger.