Omsk (Russia) (AFP) -
Leading Russian opposition figure Alexei Navalny was battling for his life in a Siberian hospital on Thursday after a suspected poisoning as Germany prepared to dispatch an air ambulance to bring him to Europe for treatment.
Navalny, a 44-year-old lawyer and anti-corruption campaigner who is among President Vladimir Putin's fiercest critics, was hospitalised in the city of Omsk after he lost consciousness on a flight and his plane made an emergency landing.
'Doctors aren't just doing everything possible. The doctors are really working now on saving his life,' the hospital's deputy head doctor Anatoly Kalinichenko told journalists in Omsk.
Navalny's spokeswoman Kira Yarmysh said he was on a ventilator in a coma and his condition was serious but stable.
'Alexei has toxic poisoning,' Yarmysh wrote on Twitter, describing how he was taken ill during the flight from the city of Tomsk to Moscow.
The hospital has not given any diagnosis while the regional health ministry said Navalny was in a natural, not induced, coma.
His team said the hospital was ill-equipped and his doctor Anastasia Vasilyeva said she had asked for the Kremlin's help to transfer him to a European clinic.
Germany Chancellor Angela Merkel joined French President Emmanuel Macron in expressing concern over Navalny's condition and said he could receive treatment in Germany or France.
'I hope that he can recover and naturally whether it be in France or in Germany he can receive from us all the help and medical support needed,' Merkel said in a joint news conference with Macron.
A German group said it was sending an air ambulance with medical equipment and specialists to Russia to pick up Navalny at 2200 GMT.
'We are in contact with the authorities and hope that all permits for the transport and a medical report for the coma patient will be given tonight,' said Jaka Bizilj, who heads the Cinema For Peace foundation.
Putin's spokesman Dmitry Peskov wished Navalny a 'speedy recovery' adding that the Kremlin would help move him abroad if needed.
Peskov said claims of poisoning were 'only assumptions' until tests proved otherwise.
Yarmysh claimed Putin was responsible for poisoning Navalny, saying: 'Whether or not he gave the order personally, the blame lies with him.'
Amnesty International urged Russia to hold a 'prompt and independent investigation'.
- 'Something in his tea' -
Navalny's wife Yulia arrived in the city about 2,200 kilometres (1,400 miles) east of Moscow and visited him.
Yarmysh said police and investigators had also arrived and journalists reported seeing FSB security service agents at the hospital.
'We think that Alexei was poisoned with something mixed in his tea. That was the only thing he drank in the morning,' Yarmysh wrote on Twitter.
She told the Echo of Moscow radio station that she was 'sure it was intentional poisoning'.
State news agency TASS cited a law enforcement source questioning this.
'We can't rule out that he drank or took something himself yesterday,' the source said, a claim Yarmysh dismissed as 'complete rubbish'.
She said Navalny had been swimming in a river the night before and was 'sober'.
Political analyst Tatiana Stanovaya said that Navalny had 'hundreds of enemies including some hardened individuals', pointing to his anti-corruption investigations that attract millions of views online.
British Foreign Secretary Dominic Raab tweeted he was 'deeply concerned' while EU foreign affairs high representative Josep Borrell wrote that if the suspected poisoning was confirmed 'those responsible must be held to account'.
US whistleblower Edward Snowden, granted asylum by Moscow, tweeted that a confirmed poisoning would be a 'crime against the whole of Russia'.
Muscovites said they suspected Navalny was poisoned over his political views.
'I think this is a deliberate attempt on his life because he has fought so fiercely with the government lately,' said 18-year-old student Yaroslav Lyangasov.
- Previous attacks -
The politician has previously suffered physical attacks, and a number of other Kremlin critics have been poisoned in the past.
He endured chemical burns to his eye in 2017 when attackers threw green dye over him. Last year Navalny said he suspected poisoning after he suffered rashes and his face became swollen while serving a short jail term for calling for illegal protests.
Yarmysh said that Navalny seemed 'absolutely fine' when they went to Tomsk airport.
'He only drank black tea in the airport,' she said.
'Straight after takeoff he quite quickly lost consciousness.'
A charismatic lawyer and whistleblower, Navalny has been travelling the country to promote a tactical voting strategy to oppose pro-Putin candidates in regional elections in September.
Navalny went to Siberia to help opposition candidates.
He has been the target of multiple criminal probes, while his Anti-Corruption Foundation is regularly raided by police and investigators.
Navalny has served numerous terms in police cells for organising illegal protests.
Thursday's incident follows other poisonings of Kremlin critics.
Britain named two Russian spies as suspects after Russian double agent Sergei Skripal and his daughter Yulia were poisoned with the nerve agent Novichok in the city of Salisbury in March 2018.
In 2006, former Russian security service agent Alexander Litvinenko was fatally poisoned with radioactive polonium in a cup of tea in London. Russia refused to extradite chief suspect Andrei Lugovoi, who became a nationalist MP.
Several other opposition figures have suffered severe illnesses in Russia that they blamed on poisoning.