By Andrew Osborn
MOSCOW (Reuters) - Russian opposition plans to convert anger over Alexei Navalny's arrest and jailing into parliamentary seats at the ruling pro-Kremlin party's expense later this year have suffered a setback after an acrimonious outbreak of infighting.
The row began on Saturday when the veteran founder of Yabloko, a storied anti-Kremlin party, urged people to turn their back on Navalny, who has emerged as the most high-profile opposition politician after his arrest and jailing sparked nationwide protests.
"Everyone must decide whether to support Navalny or not," Grigory Yavlinsky wrote in an article, which accused Navalny of being a xenophobic and authoritarian nationalist, something the 44-year-old has denied in the past.
"But you need to understand. A democratic Russia, respect for people, and a life without fear and repression are incompatible with Navalny's policies."
The intervention came ahead of parliamentary elections in September where Navalny's allies plan to encourage people to vote tactically. It has caused upheaval in Yabloko and drawn fierce condemnation from Navalny's allies, some of whom have urged Yabloko to expel Yavlinsky.
The ensuing acrimony, which has seen many people insult Yavlinsky on social media and some side with him, raises questions about whether the opposition will unite or, as in the past, mount separate challenges and squabble.
The authorities have allowed Yabloko to run in the past, although it long since failed to win enough votes to gain seats in parliament. Meanwhile, applications by Navalny's allies to register a party have repeatedly been rejected.
Some Yabloko members criticised Yavlinsky, saying he risked driving voters away at a time when people were looking for an outlet after the protests.
"Either our party can represent these people or we'll be left without voters - the only oxygen for political parties," Lev Shlosberg, a prominent Yabloko politician, wrote in a riposte.
Yevgeny Roizman, the former anti-Kremlin mayor of the city of Yekaterinburg, said he could no longer run for parliament on a Yabloko ticket.
Others said it was wrong to criticise Navalny who they said was a genuine political prisoner and unable to respond.
The row shines a light on longstanding concerns among some Kremlin opponents about Navalny's suitability to lead the opposition due to what they regard as his unacceptable views.
Yabloko expelled him in 2007 over "nationalist activities."
Navalny, who used to march with extreme nationalists and has used language about non-Russians which some critics have found offensive, said at the time that the real reason he was shown the door was his own desire to get rid of Yavlinsky.
Jailed this month for nearly three years in relation to an embezzlement case he says was trumped up, Navalny has dismissed similar criticism in the past as being motivated by personality differences and political manoeuvring.
Nikolay Rybakov, Yabloko's party leader, offered support to Yavlinsky in an interview with TV Rain.
"Yavlinsky did a very unusual thing in Russian politics. He spoke honestly to many people about what people are talking about in their kitchens but are afraid to say on social networks because they're afraid they'll be criticised," he said.
Navalny's jailing, following his return to Russia from Germany last month after being poisoned in Siberia with what many Western countries say was a nerve agent, prompted tens of thousands of people to take to the streets in protest.
His allies have called for people to gather briefly in their courtyards this Sunday and say they will call for more protests, something the Kremlin regards as illegal, in the spring. They have also called for more investigations into corruption, along the lines of hugely popular videos that Navalny has produced.
Yavlinsky said protests and investigations were not the answer. Kremlin opponents should use more conventional methods to try to win seats in parliament, he said.
(Reporting by Andrew Osborn; Editing by Peter Graff)