The following year, the local DOS administration fell apart and the DS came to power on its own; Umičević was promoted to president of the executive board.
[6] Umičević received the 240th position (out of 250) on the Democratic Party's electoral list for the National Assembly of Serbia in the 2007 Serbian parliamentary election.
[11][12] The election results were inconclusive, but ZES eventually formed a new government with the Socialist Party of Serbia (Socijalistička partija Srbije, SPS).
[13][14] He resigned from the national assembly eleven days later, contending that there was a conflict of interest between the positions and that he would need to devote more time to his responsibilities at the city level.
[15][16] As mayor, Umičević promoted a land-lease deal with the company Komiko Oil to construct a refinery on city-owned land.
The local assembly initially rejected his proposal in January 2012; Umičević blamed this on a misunderstanding, and ultimately the deal was approved in April of the same year.