By Marton Dunai
BUDAPEST (Reuters) - The Hungarian Socialist Party's candidate to be prime minister after the 2018 parliamentary election resigned on Monday, accusing a "political mafia" of undermining leftist parties he had hoped would support him.
Laszlo Botka's resignation leaves the left in disarray and cements right-wing Prime Minister Viktor Orban as favorite to win a third term in April's vote.
The Socialists governed Hungary for three terms in the 1990s and 2000s and have tried to forge a leftist coalition to unseat Orban's ruling Fidesz party.
Last week Botka, chosen as the Socialist candidate in January, made an offer to half a dozen parties to hammer out an electoral coalition, but most rejected his offer.
Botka said other parties were not fighting hard enough to replace Orban and said Fidesz had infiltrated the opposition.
"I made a mistake," Botka wrote in a statement on Monday. "I did not think democratic parties only wanted a few seats in the parliament of the Orban regime and not victory in 2018 ... I did not know how much a political mafia has infused the democratic opposition, including my own party."
The Democratic Coalition (DK), led by former prime minister Ferenc Gyurcsany, which rejected Botka's coalition offer, said: "It hurts everyone when the largest party of the democratic opposition descends into chaos like this.
"(Botka) lost support gradually, failed to gain new voters while alienating others and fellow opposition parties," said DK spokesman Zsolt Greczy.
Momentum Movement, which entered politics with its successful referendum campaign to stop Budapest's 2024 Olympic bid earlier this year, said in a statement it was this kind of "navel-gazing" that meant a new political generation was needed.
JOBBIK TO LURE LEFTISTS
Peter Jakab, a spokesman for the radical nationalist party Jobbik, which has toned down its message in an effort to capture more support, told reporters: "Not only the Socialists but the entire left-wing imploded today. "The only force to unseat the government is Jobbik."
"Jobbik offers an alternative to everyone who wants a different government. That includes leftist voters."
Socialist vice chairman Istvan Ujhelyi, a member of the European Parliament, also resigned his party post.
"Orbanistan clearly infiltrated the opposition, installing its people in nearly all potent movements," he said. "For now, it seems the coup has reached its goal: the democratic forces have become extremely divided."
The Socialists had been the strongest leftist party in opinion polls before Botka's resignation.
Socialist chairman Gyula Molnar told a news conference the party would continue to seek options to unseat Orban.
"The Socialist Party cannot on its own defeat the current regime, but I continue to see a way to cooperate with the other forces. That includes the Democratic Coalition," he said.
Fidesz, which has a firm lead in polls, said in a statement Botka's candidature "was full of scandals and his demise is not surprising ... Their next candidate will come from the same Socialist mould."
(Reporting by Marton Dunai; Editing by Janet Lawrence)