Alexei Navalny. Photo by: BBC

A Moscow court has jailed Putin critic, Alexei Navalny for three-and-a-half years for violating the conditions of a suspended sentence.

Alexei Navalny who has been in detention since returning to Russia last month, had been treated in Germany for a near-fatal nerve agent attack against him in August last year.

Thousands of supporters have rallied across Russia in support of Mr Navalny.

His suspended sentence for embezzlement has been converted into a jail term.

He has already served a year under house arrest which will be deducted from the total.

In court he called President Vladimir Putin a “poisoner”, blaming him for the attack.

His supporters called for an immediate protest and tried to gather outside court but the whole area was overrun with riot police. More than 300 have been detained, according to monitors.

His lawyer said they would appeal against the ruling.

Strong international reaction to the sentence came quickly, with the Council of Europe – the continent’s leading human rights body – saying the judgement “defied all credibility”.

UK Foreign Secretary, Dominic Raab described the ruling as “perverse”, and US Secretary of State Antony Blinken said he was deeply concerned by it.