MEP Klára Dobrev won the first round of a primary race to become Hungary’s joint opposition candidate for prime minister, according to results published late Thursday.

The primary voting is part of an effort by an alliance of six opposition parties to present a united front when challenging Prime Minister Viktor Orbán in a parliamentary election next year.

Dobrev, who serves as a vice president of the European Parliament, received 214,319 votes — 34.8 percent of the total. Late Thursday, she called the result a “historic success.”

A member of the left-liberal Democratic Coalition — part of the Socialists and Democrats group in the European Parliament — Dobrev is known as an energetic campaigner. She is married to a former Hungarian prime minister, Ferenc Gyurcsány, who still leads the Democratic Coalition.

Opposition supporters voted in person and online to select joint candidates both in electoral districts and for the post of prime minister.

Environment-friendly Budapest Mayor Gergely Karácsony came in second place with 27.3 percent of the vote, and the conservative mayor of the southern city of Hódmezővásárhely, Péter Márki-Zay, came in third with 20.4 percent.

The top three candidates will now face off in a second round of voting, to be held between October 4 and October 10.

Out of the race are right-wing Jobbik party’s leader, Péter Jakab, who garnered 14.1 percent, and András Fekete-Győr of the centrist Momentum Movement — part of the Renew Europe group — who came in last place with 3.4 percent.

On Thursday night, Karácsony, the Budapest mayor, asked voters to consider in the second round of voting which candidate would be able to expand the base of opposition voters and appeal to undecideds.

“We have to do everything to unite Hungary once again,” he said.