[3] After the overthrow of Slobodan Milošević, Jovanović was selected by the Democratic Opposition of Serbia to be one of its MPs, and he subsequently became the youngest parliamentary caucus leader in Serbian history, at the age of 29.

As a result of the clashes Jovanović was one of five representatives of the protest movement which met with General Momčilo Perišić and Internal Affairs Minister Zoran Sokolović.

On the morning of 6 February 2001, Jovanović sat in a restaurant by the business club "Lutra" to attend a discussion with State Security executive Franko Simatović, the Minister of Interior Dušan Mihajlović, and Milorad Ulemek, who organised the meeting.

[14] Jovanović and Mihajlović asked Simatović about the Ibar Highway assassination attempt on Vuk Drašković, the murder of Slavko Ćuruvija and the disappearance of Ivan Stambolić.

[8] On 31 March 2001, after a masked government unit stormed Slobodan Milošević's fortified villa, Jovanović negotiated with the former Yugoslav president for him to surrender peacefully.

It has been alleged that during his mandate as Member of Parliament, in addition to his regular duties, Jovanović assumed the role of Prime Minister Đinđić's government liaison - dealing with, and meeting individuals connected to Serbian organised crime circles.

Political opponents directly accused him of criminal involvement and of providing favours for shady individuals such as Dušan Spasojević (late leader of the Zemun mafia clan) and Milorad Ulemek (now convicted as the person who organised the assassination of Zoran Đinđić).

After continuous pressure from the media, Jovanović admitted to attending some meetings, but denied any wrongdoing, claiming that these contacts were made on behalf of the government in order to curb mafia activities and to secure political stability from the individuals left over from the Milošević's era.

Dissatisfied with the party's new direction under the leadership of Boris Tadić, Jovanović criticised him publicly, most notably for his policy of political cohabitation with Prime Minister Vojislav Koštunica's government.

Being a fierce Koštunica opponent, Jovanović felt that the Democratic Party should actively seek ways to bring down his government, especially when Boris Tadić was elected President of the Republic in June 2004.

A couple of months after Tadić's inauguration, Jovanović wrote his party colleague an open public letter[17] on a per tu basis criticising his political choices.

Tadić never even acknowledged the letter publicly until he was directly asked about it during an interview on a weekly political TV talk show Utisak nedelje.

He repeatedly criticised the Serbian Orthodox Church, calling it dishonest, backward and dogmatic, protesting what he sees to be its interference in the country's politics.

Parallel to all of this Jovanović also founded a non-governmental organisation called Center for Modern Politics (Centar za modernu politiku, CMP), but its activities were sporadic at best and it eventually folded.

Soon after, in December, he was the subject of a lengthy, very affirmative piece penned by Zoran Ćirjaković in the influential American weekly magazine Newsweek which, among other things, Jovanović used to further reiterate his stance on Kosovo and to declare his opinion that Bosnian Serb ties with Belgrade should effectively be severed.

With an aggressive "Od nas zavisi" campaign, he was hoping to ensure enough votes for LDP to become a significant factor when it comes to forming the ruling coalition.

In November 2007, in anticipation of presidential election, Jovanović opened a public row with powerful and politically connected Serbian tycoon Miroslav Mišković.

On Sunday, 18 November 2007, while guest on Utisak nedelje, a weekly television political talk-show, Jovanović claimed Mišković tried to get himself off the US entry visa blacklist, in exchange offering the American embassy in Belgrade to arrange prime minister Koštunica's cooperative and soft stance when it comes to the final status of the Serbian province of Kosovo whose independence America firmly supported.

[20] Amid the controversy that was immediately raised, the next day, Monday, Jovanović went on B92 radio's morning talk-show Kažiprst, claiming that Mišković's liaison in this particular endeavour with the Americans was a well-known Belgrade journalist, stopping short of revealing his name.

[22] Jovanović responded by filing an official complaint against Mišković in the Serbian police and publicly releasing a 4-page supposed internal Belgrade's American embassy document dated May 2007 in support of his earlier statements.

[30] In the debate, Jovanović defended a previous statement he made saying that "Republika Srpska was founded on genocide and ethnic cleansing", referring particularly to the Srebrenica massacre.

In March 2011, during a parliamentary session about the 2011 Libyan civil war, Jovanović tried to criticise Serbia's Foreign Minister Vuk Jeremić on his visits to various countries in Africa at the time.

[32] His wife, Jelena, is from Nevesinje, Bosnia and Herzegovina[33] She is the owner of "Agroposlovi",[34] a Belgrade based business that operates a larger company named Fidelinka from Subotica, Serbia.