A Foreign, Commonwealth & Development Office spokesperson said:
Today the Russian Ambassador to the UK was summoned to the Foreign, Commonwealth and Development Office. The UK Government registered its deep concern with the Russian Government about the poisoning of Alexey Navalny with a chemical nerve agent from the Novichok group.
The Foreign Secretary has made it clear that it is absolutely unacceptable that a banned chemical weapon has been used, and that violence has again been directed against a leading Russian opposition figure. There is a case here for Russia to answer. This took place on Russian soil, against a Russian citizen. They have international obligations to uphold. This is nothing short of an attack against the rules based international system which keeps our societies safe.
Russia needs to conduct a full, transparent criminal investigation into Mr Navalny’s poisoning. We will work with our partners, including through action in the OPCW, to hold the perpetrators to account.