During his political career, Milovanović was the leader of the Association of Free and Independent Trade Unions (Asocijacija slobodnih i nezavisnih sindikata, ASNS) and the Labour Party of Serbia (Laburistička partija Srbije, LPS).
Serbian political life in this period was dominated by the authoritarian rule of Socialist Party of Serbia (Socijalistička partija Srbije, SPS) leader Slobodan Milošević, and Milovanović became an active opponent of the administration.
The following year, he was active in seeking the release of Serbian Renewal Movement (Srpski pokret obnove, SPO) leaders Vuk and Danica Drašković from prison.
[6] Zajedno was successful at the local level in Belgrade and other major cities, but its victories were not initially recognized by the state authorities; this prompted large-scale civic protests against Milošević's administration.
Milovanović brought the ASNS into the protests in December 1996, an event considered significant in that it was the first time organized labour had taken part in a major anti-government action in Milošević's Serbia.
Responding to a suggestion that those made unemployed by the bombing would be asked to help with Serbia's reconstruction, he said, "This regime should know the workers will not work for them for peanuts any more, nor will they rebuild the country for free.
[12][13] In 2000, Milovanović brought the ASNS into the Democratic Opposition of Serbia (Demokratska opozicija Srbije, DOS), a broad and ideologically diverse coalition of parties opposed to the Milošević administration.
[14] The ASNS was a frequent rival to the Confederation of Autonomous Trade Unions of Serbia (Savez Samostalnih Sindikata Srbije, SSSS), which was generally aligned with Milošević.
As in 1996, the Milošević regime did not initially accept defeat, and a new wave of civic protests took place against the government; Milovanović participated in these events, helping to organize road blockades.
The first members of this body were chosen by indirect election from the republican parliaments of Serbia and Montenegro, with each parliamentary group allowed representation proportional to its numbers.
[34] In April of the same year, he announced forthcoming legislation on health and occupational safety and the registration of trade unions and employers' organizations.
[35] Serbia generally experienced economic instability in the early years after Milošević's fall from power, and much of the population faced precarious employment during Milovanović's time in office.
His tenure as a cabinet minister ended when a new coalition government was formed in early 2004; one of his last acts in office was to announce a further increase in the minimum wage in February 2004.
The ASNS made a formal alliance with the LDP for the 2012 Serbian parliamentary election, and Milovanović appeared in the twenty-ninth position on the LDP-led Preokret (English: U-Turn) coalition list.
He was later given the twenty-third position on the LDP's list in the 2014 parliamentary election; on this occasion, the party did not cross the electoral threshold for assembly representation.