Mayor of Hodmezovasarhely and conservative opposition candidate for prime minister, Peter Marki-Zay, leader of independent civic political initiative "Everyone's Hungary Movement" speaks at a campaign rally during the second round of the opposition primary election, in Budapest, Hungary, October 10, 2021.

BUDAPEST, Oct 17 (Reuters) - Small-town conservative Peter Marki-Zay, a political outsider with no party affiliation, will go head-to-head with Prime Minister Viktor Orban next year for leadership of Hungary after on Sunday winning an opposition run-off primary.

Marki-Zay defeated leftist Klara Dobrev, who pledged to support him at the head of an alliance of six opposition parties that, in the 2022 parliamentary election, will bid to oust Orban after more than a decade in power.

For the first time since he came to power in 2010, Orban will next year face a united front of opposition parties that also includes the Socialists, liberals and the formerly far-right, now centre-right, Jobbik.