Russia cautioned Switzerland on Tuesday that any attempt to impose sanctions for alleged illegal activities on Swiss soil would undermine its position of neutrality.
A blunt intervention from Russia's ambassador to Switzerland Sergei Garmonin comes just days after Switzerland's authorities said they were investigating two suspected Russian spying cases.
Mr Garmonin has been summoned to the Swiss foreign ministry three times already this year over concerns about alleged espionage activities.
On Sunday, the Swiss foreign ministry said it was calling on Russia “to immediately end illegal activities on Swiss soil or against Swiss targets”.
Reacting to the comments, Mr Garmonin said diplomatic relations between the two countries would suffer should Bern decide to punish Moscow.
"Such a step would be contrary to Bern's declared neutrality policy and would cause serious damage to the Russian-Swiss ties," he told Sputnik.
The Swiss government confirmed reports on Friday that it had foiled a Russian plot with the help of Britain and the Netherlands allegedly targeting a laboratory 40 kilometres away from Bern.
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Media reports said that two suspected Russian spies, who were later arrested by Dutch authorities, had selected the laboratory because it was testing the nerve agent used to attack former Russian double agent Sergei Skripal in Britain.
Britain has blamed Russia for the attack, which happened in the English city of Salisbury in March this year, and has charged two Russian nationals in absentia. Moscow denies any involvement.
Mr Garmonin accused Swiss media of using inflammatory rhetoric to try and change the country’s position towards the Kremlin.
“I think that certain well-known circles, who are trying to force Switzerland to change the traditional, independent and neutral approach to the international affairs and take a more confrontational attitude towards Russia, are behind these 'revelations’," he said.
Swiss prosecutors revealed on Saturday that they were also investigating a suspected Russian cyber attack on the offices of the World Anti-Doping Agency (WADA) in March 2017.
The agents suspected of carrying out the WADA attack are the same pair being held in the Netherlands, the attorney general’s office said.
The agency had been investigating reports of doping by Russian athletes and resulted in Russia being banned from competing in the Olympics for three years.
Russia finds out on Thursday whether it will be readmitted to the sporting community at a meeting of WADA chiefs in the Seychelles.