The European Parliament on Thursday demanded tough EU sanctions on Russia over the poisoning of opposition leader Alexei Navalny, accusing the Kremlin of trying to assassinate him to silence dissent.

Members of the assembly said the poisoning of Navalny with the Novichok nerve agent was part of a “systemic effort” by President Vladimir Putin’s government to stifle opposition.

Navalny collapsed last month on a domestic flight in Russia after a campaign trip to support opposition candidates in local elections and is now being treated in Germany, where experts confirmed he had been poisoned with the Soviet-era nerve agent.

“Political assassinations and poisonings in Russia are systemic instruments of the regime deliberately targeting the opposition,” the European Parliament said in a non-binding resolution, adding that Novichok was “only available to military structures and secret services in Russia”.

“The attempted assassination of Alexei Navalny was part of a systemic effort to silence him and other dissident voices, and to deter him and those voices from further exposing serious corruption in the regime and deter political opposition in the country in general.”

The resolution urged the EU to “establish as soon as possible a list of ambitious restrictive measures vis-a-vis Russia and strengthen its existing sanctions against Russia” — though the European Parliament has no power to initiate such measures.

After the poisoning of ex double agent Sergei Skripal and his daughter in Britain — an attack that also used Novichok — the EU sanctioned several members of Russian military intelligence.

But in the Navalny case, no culprits have so far been identified, making it impossible to impose individual sanctions.

Russian Foreign Ministry spokeswoman Maria Zakharova said any move to create sanctions in Navalny’s name would be “manifestly anti-Russian” and accused Western governments of not wanting to find out the truth about what happened to him.

“The real goal of the EU’s campaign is to ensure the continuation of the destructive course adopted by the EU against our country,” she said.