A host of British MPs have called for action following the arrest of Russian opposition leader Alexei Navalny.

Mr Navalny was detained at a Moscow airport on Sunday after spending five months in Germany recovering from nerve agent poisoning that he blames on the Kremlin.

Prior to his arrival at Moscow’s Sheremetyevo airport, Russia’s prisons service said the 44-year-old had violated parole terms from a suspended sentence on a 2014 embezzlement conviction.

Mr Navalny with his wife Yulia
Mr Navalny with his wife Yulia. Mr Navalny was detained on arrival at a Moscow airport (Mstyslav Chernov/AP)

Following the news of his arrest, a number of British MPs used Twitter to call for his release.

Shadow foreign secretary Lisa Nandy led the calls for action, tweeting: “Alexei Navalny was the victim of a cowardly chemical weapons attack. He has shown great courage in returning to his homeland.

“His detention is unjustifiable and an insult to the Russian people. He must be released immediately and his attackers brought to justice.”

SNP defence spokesman Stewart McDonald was equally forceful in his condemnation of Mr Navalny’s arrest.

He wrote on Twitter: “Having failed to crush @navalny’s bravery with poison the Russian Government will now try, and fail, by putting him in prison.

“The free world must stand in unison in calling for his release. Those who continue to shill for Putin’s various outlets must surely feel shame tonight.”

Labour MP Catherine West called for a coordinated response from the UK Government, the European Union and the incoming Joe Biden administration in the US.

She said: “The UK govt. must work at speed with EU partners & the Biden team to develop a robust response following the arrest of #Navalny in Moscow.

“It cant be right that an opposition leader, whose life was almost taken in an aggressive poison attempt, is arrested on arrival.”

Defence committee chairman Tobias Ellwood called Mr Navalny’s decision to return to Russia “incredibly brave”, in a sentiment echoed by veterans minister Johnny Mercer.

Mr Ellwood said: “Poisoned by the FSB yet he chooses to return to Russia and has now been arrested.

“Incredibly brave stand by #Navalny in the name of democracy as we head towards Russian parliamentary elections.

“I hope the FCDO is monitoring events closely.”

A statement from the Foreign, Commonwealth & Development Office (FCDO) said: “We are deeply concerned by the detention on 17 January of Alexei Navalny.

“Instead of persecuting the victim of this terrible crime, the Russian authorities should investigate how a chemical weapon came to be used on Russian soil.”