Chief Kremlin critic Alexei Navalny returns to Russia from Germany on Sunday, facing imminent arrest after authorities warned they would detain him.
The 44-year-old opposition leader is flying back to Moscow after spending several months in Germany recovering from a poisoning attack that he said was carried out on the orders of President Vladimir Putin.
Navalny fell violently ill on a flight over Siberia in August and was flown out to Berlin by medical aircraft in an induced coma.
Western experts concluded he was poisoned with a Soviet-designed nerve toxin Novichok.
The Kremlin denied involvement and Russian investigators said there were no grounds to launch a probe into the attack.
Berlin said Saturday it had responded to requests for legal assistance from Moscow and handed over transcripts of an interview conducted by German police with Navalny.
On the eve of his departure Navalny thanked the people in Germany, including doctors, police and politicians, whom he met during his five-month stay.
"Thank you, friends!" he wrote in German in a post on Instagram.
Warning against airport crowds
Russia's prison service (FSIN) is now saying Navalny may face jail time on arrival to Moscow for violating the terms of a 2014 suspended sentence he was handed on fraud charges.
FSIN said it would be "obliged" to detain Navalny.
The anti-graft campaigner may also face criminal charges under a probe launched by Russian investigators late last year who say he misappropriated over $4 million worth of donations.
Navalny and his allies view these moves as attempts to prevent his return and encouraged supporters to come meet the opposition leader on Sunday evening when he lands in Moscow's Vnukovo airport.
More than 2,000 people said they are planning to go in a Facebook event despite temperatures in Moscow hovering around -20 degrees Celsius (-4 degrees Fahrenheit).
Several activists in Russia's second city Saint Petersburg, who were travelling to Moscow to greet Navalny, said they were stopped by police at the city's train station and airport.
Groups opposed to Navalny are also planning to show up with a nationalist movement promising to welcome him with "zelyonka", a bright green antiseptic solution that is commonly found in Russia.
Navalny had previously been attacked with the green dye that can take days to wash off.
For around a decade, Navalny has been the symbol of Russia's protest movement, after rising to prominence as an anti-corruption blogger and leading anti-government street rallies.
Navalny's team publishes YouTube investigations into the wealth of Russia's political elites, some of which garner millions of views, making them a target of lawsuits, police raids and jail stints.
Moscow prosecutors on Friday warned against participating in the "public event" organised in Vnukovo airport, saying it has not been authorised.
Videos shared on social media showed riot police already parked outside the airport.
The airport told journalists that it will not allow media to work inside citing coronavirus concerns.
Neither statements directly mention Navalny -- a common practice for Russian authorities and pro-Kremlin media which instead refer to him as the "Berlin patient" among other euphemisms.
Negative state media coverage
Navalny is ignored or given negative coverage by state-controlled TV, the primary source of news for many Russians, which makes it unclear how much support Navalny enjoys among ordinary citizens.
According to a poll published by the independent Levada Centre last year, only 20 percent of respondents said they approved of Navalny's actions, while 50 percent disapproved.
Navalny has never held elected office. He came second in a 2013 vote for mayor of Moscow but was barred from standing against Putin in the 2018 presidential elections.
His allies are also frequently prevented from running for election.
In 2019, several Navalny allies were barred from running for the Moscow city council, sparking mass rallies in the capital that lasted several weeks.
With elections to the country's lower house State Duma coming up in September, protest sentiments among Russia's opposition would be unfavourable to the ruling United Russia party.
Observers say the Kremlin is faced with a choice on Sunday: let Navalny roam free and risk looking weak, or arrest him in front of hundreds of people and cameras, sparking an outcry from the opposition.
"I have a feeling the Kremlin has grown tired of these games," analyst Tatyana Stanovaya told AFP. "The confrontation with Navalny has been going on for