Russia’s Foreign Ministry says it is expelling diplomats from Sweden, Poland and Germany for attending a rally in support of opposition leader Alexei Navalny

The announcement came as the European Union’s top diplomat told Russia’s foreign minister that the treatment of Mr Navalny represents “a low point” in relations between Brussels and Moscow.

The ministry said diplomats from Sweden and Poland in St Petersburg and from Germany in Moscow took part in “unlawful” rallies on January 23. Tens of thousands of people across Russia took to the streets that day to protest against the arrest of Mr Navalny, the Kremlin’s most prominent critic.

The diplomats were declared “persona non grata” and were required to leave Russia “shortly”, a ministry statement said.

EU foreign affairs chief Josep Borrell, who earlier met Foreign Minister Sergey Lavrov, said before the session that “our relations are under a severe strain, and the Navalny case is a low point in our relations”.

Sweden “considers this entirely unjustified, which we have also conveyed to the Russian side”, Foreign Ministry spokesman Mats Samuelsson said, adding that Stockholm “strongly rejects Russian claims that the diplomat took part in a demonstration in Russia” and “reserves the right to take appropriate measures in response”.

German Chancellor Angela Merkel echoed his statement, saying: “We consider this expulsion unjustified and think it is another facet of the things that can be seen in Russia at the moment that are pretty far from the rule of law.”

French President Emmanuel Macron condemned the expulsions and what happened to Mr Navalny “from the beginning to the end”, and expressed solidarity with Germany, Poland and Sweden.

Mr Navalny, 44, an anti-corruption investigator and Russian President Vladimir Putin’s most prominent critic, was arrested on January 17 on returning from Germany, where he spent five months recovering from a nerve-agent poisoning that he blames on the Kremlin. Russian authorities have rejected the accusation.

On Tuesday, a Moscow court ruled that while in Germany, Mr Navalny violated probation terms of his suspended sentence from a 2014 money-laundering conviction, and ordered him to serve two years and eight months in prison. The ruling prompted international outrage.

After his meeting with Mr Lavrov, Mr Borrell said he had relayed his concerns over Mr Navalny’s jailing and the arrests of thousands of people who demonstrated in his support.

The EU official said he also communicated the bloc’s support for Mr Navalny’s release and for an investigation of the August poisoning.

Mr Lavrov again accused European officials of refusing to share evidence of the poisoning. The Kremlin has said it will not listen to Western criticism of Mr Navalny’s sentencing and police action against his supporters.

In the mass protests, many demonstrators chanted slogans against Mr Putin in the largest show of discontent in years. Thousands were detained.

Mr Navalny was back in court on Friday for yet another trial — this time on the charge of defaming a Second World War veteran featured in a pro-Kremlin video that Mr Navalny criticised on social media last year.

A criminal investigation of the politician was opened after he condemned people featured in a video promoting constitutional amendments that allowed an extension to Mr Putin’s rule, calling them “corrupt stooges”, “people without conscience” and “traitors”.

Russian authorities said his comments “denigrate (the) honour and dignity” of a a war veteran featured in the video. If convicted, he faces a fine or community service.

He has denied the charge and refused to plead guilty on Friday, calling the trial a “PR process” aimed at discrediting him.

“The Kremlin needs headlines (saying that) Navalny slandered a veteran,” he said.

The 94-year-old veteran, Ignat Artemenko, took part in the hearing by teleconference, saying he was distressed by Mr Navalny’s comments and demanding a public apology.

The judge ordered a recess several hours after the hearing started, citing Mr Artemenko’s health.