A member of the Krkobabić political family, he has led the Party of United Pensioners, Farmers, and Proletarians of Serbia (PUPS) since 2014.

It contested the 2007 Serbian parliamentary election on a combined electoral list with the Social Democratic Party (SDP), and Krkobabić was included in the 105th position.

Krkobabić was not a candidate at the republic level in that year but instead received the second position on a SPS-led list in the concurrent 2008 Belgrade city assembly election.

The PUPS participated in the new governments, and Krkobabić said it would use its influence to fight for a pension increase and resist any efforts to impose neoliberal reforms.

[9] Krkobabić later defended Belgrade's decision to erect a statue of former Azerbaijani president Heydar Aliyev in Tašmajdan Park, which the government of Azerbaijan had donated two million Euros to renovate following extensive damage in the 1999 NATO bombing of Yugoslavia.

"[18] In the same period, Krkobabić said that the corporation would focus on completing a number of capital investment projects, including a central postal hub in Belgrade.

[20] Despite its alliance with the Socialists and Progressives at the republic level, the PUPS initially continued to work in a coalition government with the DS in Belgrade.

In this period, Krkobabić supported Đilas's administration at the city level and opposed the SNS's efforts to change the government.

The Progressive Party and its allies won a majority victory and afterward formed a new coalition government that again included the Socialists.

The PUPS did not participate directly in the government but provided outside support; notwithstanding his exchange with Vučić in the campaign, Krkobabić became part of the latter's assembly majority.

In July 2014, he indicated that the PUPS would support two contentious bills dealing with changes to labour law and pension and disability insurance.

[38] The following year, he and Rasim Ljajić, Serbia's minister of trade, tourism, and telecommunications, signed a collective agreement with Pošta Srbije workers that, among other things, confirmed their right to a share of the corporation's profits.

[40] The PUPS ended its electoral alliance with the Socialist Party and formed a new partnership with the Progressives for the 2016 Serbian parliamentary election.

[43] He was later given further responsibilities as chair of Serbia's council for coordination of activities and measures for gross domestic product (GDP) growth.

[45] Shortly after this, he announced a significant government investment in agricultural co-operatives to ensure that younger people could choose to live in rural settings.

[61] He resigned his assembly seat on 30 April 2024 after being re-appointed as minister of rural welfare in Serbia's new ministry under Miloš Vučević.

[62][63] In October 2024, he announced that 3,309 houses in total had been purchased under his department's program for young people to return to the countryside.