EU ministers seized by Navalny health crisis

"I am deeply worried about Alexei Navalny's health. He must immediately receive access to proper medical treatment," European Commission chief Ursula von der Leyen added.

The US and the UK issued similar statements.

The alarm comes after Navalny spent three weeks on hunger strike over prison authorities' refusal to let him see outside doctors.

His associates said in a letter to EU foreign ministersthat he was already suffering from "multiple hernias and protrusions in his spine" and a "heavy cough and fevers", which could indicate he had contracted tuberculosis, before his hunger protest began.

But in the past few weeks, he has lost 9kg in weight and his blood potassium levels have soared to levels putting him in danger of kidney failure or cardiac arrest.

"Our patient can die any minute", Yaroslav Ashikhmin, a Russian cardiologist wrote on Facebook on Saturday.

His wife and daughter also appealed for inernational help.

And his supporters have planned mass protests in Russia on Wednesday, gathering some 450,000 signatures in support of the move in a sign of how big the demonstrations could get.

Meanwhile, Hollywood stars, including Jude Law, Ralph Fiennes, and Benedict Cumberbatch, published an open letter in European media calling for him to get proper care.

But Russia's ambassador to the UK, Andrei Kelin, told the BBC on Sunday: "I can say that Mr Navalny behaves like a hooligan absolutely in trying to violate every rule that has been established".

"His purpose for all of that is to attract attention for him[self]," he added.

Russia is also taking steps to designate his FBK anti-corruption foundation as an "extremist organisation", meaning that its members could be jailed for years as "terrorists".

Its hard line toward European concern over its aggressive behaviour was mirrored in its expulsion, this weekend, of 20 Czech diplomats.

It did so after Prague expelled 18 Russian diplomats, whom it said were spies, after concluding that Russian operatives were behind an explosion at an ammunition depot in the country in 2014.

"In their desire to please the United States against the background of recent US sanctions against Russia, Czech authorities in this respect even outdid their masters from across the pond," the Russian foreign ministry said.

Russian operatives, in recent years, also carried out assassinations and assassination attempts in Germany and in the UK.

Meanwhile, the EU ministers will hold video-talks with Ukrainian foreign minister Dmytro Kuleba over Russia's military build-up around Ukraine, in what looks like preparation for a major offensive in May.

Kuleba has urged Borrell to visit the front line in a show of solidarity, with Borrell's office earlier telling EUobserver he already had "a longstanding plan" to do so.

Borrell's reference to "holding Russia to account" on Navalny could mean further sanctions.

The EU earlier blacklisted several Russian officials over Navalny's poisoning with a chemical weapon and his subsequent jailing.

It has created a much longer blacklist of Russians over its seven-year long war on Ukraine, as well as restricting business ties with Russian banks and energy firms and blocking any business ties with Russia-occupied Crimea in Ukraine.

But the German government has resisted calls to halt a new Russia-Germany gas pipeline, called Nord Stream 2, despite the escalating tensions.

"Russia has murdered people in broad daylight in Berlin, it has interfered in EU and US elections, and conducted cyber-attacks on European institutions, but, at the same time, it has corrupted the German business elite to such an extent that nobody in Berlin wants to stop the pipeline," an EU diplomat told EUobserver.

The EU ministers will also discuss the war in Ethiopia and jihadist massacres in Mozambique, as well as a political crisis in Georgia and post-coup slayings of protesters in Myanmar.