BUDAPEST, Oct 17 (Reuters) - Peter Marki-Zay, the small-town mayor who will take on Prime Minister Viktor Orban in Hungary"s 2022 election, figures his conservative, family-man persona will leave nationalist Orban floundering in next year"s vote. Marki-Zay beat left-wing front-runner Klara Dobrev in an opposition primary on Sunday in a major upset, as only two of the six opposition parties had endorsed him before the vote. The 49-year-old father of seven, who has degrees in economics, marketing and engineering, rose to prominence when he won a 2018 mayoral contest in his hometown, a stronghold of the ruling Fidesz party. Portraying himself as a palatable choice for both left-wing and conservative voters, Marki-Zay had said the opposition stood no chance of defeating Orban with Dobrev, the wife of former prime minister Ferenc Gyurcsany, one of the most divisive figures in Hungarian politics. "This (contest) is about whether we will be free," Marki-Zay told a news conference after Budapest"s leftist mayor, Gergely Karacsony, withdrew from the race in his favour last week. "Whether Hungary will remain a European country or it sinks. It loses its track and turns towards the east, becoming a corrupt dictatorship, from which its own people are fleeing." Marki-Zay"s family-man image and Catholic faith, which fit well with the ideology embraced by Orban, could make it harder for Fidesz to vilify him, as the ruling party has portrayed top leftist candidates in the running as Gyurcsany"s puppets. "If I were to win the candidacy, (Fidesz) would have to dump all of its playbooks," Marki-Zay has said, slamming Orban"s past manoeuvring, which saw the 58-year-old premier turn from a fiery liberal into a nationalist self-appointed defender of Christian values. Marki-Zay, founder of the grassroots Everyone"s Hungary Movement (MMM), has promised to jail those responsible for what he has described as "theft from state coffers" and pledged to rewrite Orban"s constitution via a referendum. He is also looking to annul laws that have helped cement Orban"s power, and to restore the autonomy of local governments. Marki-Zay also said he would adopt the euro. Only the leftist Momentum and the Socialists formally endorsed Marki-Zay before the run-off, while others hedged their bets, saying they would back the eventual winning candidate.