Britain said Thursday it was "concerned" at the guilty verdict against Russian opposition leader Alexei Navalny, saying it raised questions about the rule of law.
Navalny was found guilty Wednesday of embezzlement and given a five-year suspended sentence that threatens to end his bid to challenge President Vladimir Putin in next year's presidential elections.
"We are concerned at the conviction handed down to Russian opposition politician, Alexei Navalny," Britain's Foreign Office said in a statement.
"The judgement once again raises questions about the selective application of the rule of law in Russia."
The ministry said the case reflected "a worrying trend in Russia" of opposition voices being silenced.
"The UK urges Russia to uphold the principles of democracy and support political pluralism."
A judge in the provincial city of Kirov found the Kremlin critic and anti-corruption campaigner guilty at a trial that he insists was aimed at knocking him out of the election expected in March 2018.
Navalny condemned the verdict as a "telegram from the Kremlin".
The court was holding a retrial after Navalny and his co-defendant, businessman Pyotr Ofitserov, were convicted of alleged embezzlement in 2013.
The European Court of Human Rights last year quashed the ruling, saying the men did not have a fair trial.
But Russia's supreme court then ordered that Navalny and Ofitserov face a retrial.
British Prime Minister Theresa May earlier Thursday demanded international pressure on Russia over an upsurge of violence in eastern Ukraine.
During a meeting with Italian Prime Minister Paolo Gentiloni, May "emphasised the UK's continuing concern over Russia's aggressive and destabilising actions and the drastic deterioration in the humanitarian situation.
"It is vital that the international community continues to exert pressure and that we continue to maintain sanctions on Russia until the Minsk agreements are fully implemented."