By Lefteris Papadimas and Karolina Tagaris
ATHENS (Reuters) - The leader of Greece's far-right Golden Dawn party was sent to jail on Thursday pending trial on criminal charges, the first time an elected party chief has been put behind bars since a military coup nearly five decades ago.
The imprisonment of Nikolaos Mihaloliakos, who has watched support for his party wane after a supporter fatally stabbed a popular rapper, is a reprieve for Prime Minister Antonis Samaras's government that has vowed to wipe out the party, calling it a "gang of neo-Nazis".
Stunned by a court decision to free three other senior Golden Dawn lawmakers on Wednesday, the government hailed Thursday's verdict as "the most dynamic confrontation of a neo-Nazi criminal gang in European, and possibly, world history".
The government, which is hoping the mass arrests of Golden Dawn's top brass will help it subdue a party seemingly untouched by accusations of violence and intimidation, praised the justice system for "doing its job".
Mihaloliakos, grey-haired and bespectacled, shouted: "Long live Greece! Victory!" as he was led away from court in handcuffs in the early hours of Thursday. He denied charges of founding and belonging to a criminal organization during a six-hour plea session before a judge.
His wife and daughter, joined by Golden Dawn lawmakers, stood outside the court in the rain. "You are a diamond - don't buckle," his wife Eleni Zaroulia, a fellow lawmaker, told him.
Flag-waving supporters yelled a popular party slogan: "Blood! Honor! Golden Dawn!".
Mihaloliakos, who was arrested on Saturday alongside other party members, will be transferred to a high security prison later on Thursday.
His deputy, Christos Pappas, who turned himself in on Sunday, arrived at the heavily guarded court to respond to charges. Another lawmaker, Yannis Lagos, was sent to jail on Wednesday pending trial.
Golden Dawn said the decision was "the most wretched conspiracy in modern Greek political history".
"The jailing of our general secretary is totally unfair, unconstitutional and dictated by foreign centers of power," the party said in a statement posted on its website.
Another party member was also detained pending trial after responding to the same charges, a court official said.
On Wednesday, three senior Golden Dawn lawmakers were freed pending trial. That decision had raised questions about the state's case against Golden Dawn after one of its sympathizers stabbed anti-racism rapper Pavlos Fissas to death last month.
Party spokesman Ilias Kasidiaris and fellow lawmakers Ilias Panagiotaros and Nikos Michos stormed out of the court celebrating their release as they kicked and spat at journalists and punched a camera out the way.
"I wonder how they can celebrate with such accusations on their back," Public Order Minister Nikos Dendias told a Greek newspaper who described the scene as "repulsive, ugly and indicative of their neo-Nazi mentality."
"But let's not kid ourselves ... they're Nazis, they behave like Nazis," Dendias said.
Golden Dawn, for years a little-known group, rode a wave of anger at traditional parties, corruption and the country's deep economic crisis to win 18 seats in parliament in last year's election.
But the killing of Fissas prompted protests across Greece and a crackdown on a party which features a swastika-like emblem and is accused of violent attacks on dark-skinned immigrants and political opponents, something it denies.
The 45-year-old man who admitted to stabbing Fissas in the heart and chest last month has been charged with premeditated murder and sent to jail.
Despite shedding about a third of support since the killing, polls show it remains Greece's third most popular party.
"Every time they want to take measures against the people they always bring to light something else. Something big ... and then suddenly we have more taxes," said pensioner Antonis Lavdas.
(Additional reporting by Phoebe Fronista, Tatiana Fragou, Gina Kalovyrna, Renee Maltezou and George Georgiopoulos; Writing by Karolina Tagaris, editing by Elizabeth Piper)