In a joint statement reiterating their "outrage", the leaders said they were completely confident the attempted killing of former Russian double agent Sergei Skripal on British soil in March "was nearly certainly approved at a senior government level" in Russia.
In her statement to the MP's, she alleged that it is not only United Kingdom, but also the other westerns nations that are planning to take action against the GRU, the Russian intelligence service.
The case, with its chilling cloak-and-dagger details, echoes the 2006 murder of Alexander Litvinenko, a former Russian agent who died after drinking tea laced with radioactive polonium-210 at a London hotel.
"This was not a rogue operation", Prime Minister Theresa May said of the two suspects believed to be part of the GRU, Russia's Main Intelligence Directorate.
"They must rein in the activities of the GRU".
"Just as the police investigation has enabled the CPS to bring charges against the two suspects, so the security and intelligence agencies have carried out their own investigations into the organisation behind this attack, " she said.
Security Minister Ben Wallace said that Putin was "ultimately" responsible for the poisoning in the southwestern city of Salisbury - prompting an angry response from Moscow.
Mr Putin's spokesman, Dmitry Peskov, said the accusations were unacceptable and claimed that "neither the Russian leadership nor its representatives have anything to do with the events in Salisbury".
Relations between Canada and Russian Federation have not been spared, with the two countries involved in various wars of words and tit-for-tat diplomatic expulsions - including one round in March that was in direct response to the Salisbury attack.
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However, researchers point out that, while the relative risk increased significantly, the overall risk was still pretty small. Also, it's important to note that this is an observational study, so no cause-effect relationship was established.
Britain and dozens of other countries have kicked out scores of Russian diplomats over the incident, and Moscow has responded tit-for-tat with an identical number of expulsions.
British authorities said that a European arrest warrant had been issued for the two Russians, identified as Aleksandr Petrov and Ruslan Boshirov, although it is suspected the names are aliases.
He added: "I don't think anyone can ever say that Mr Putin isn't in control of his state".
On 30 June 2018 a similar poisoning of two British nationals in Amesbury, seven miles from Salisbury, involved the same nerve agent.
"We retaliate in our way. within the rule of law and in a sophisticated way, so they know the cost of what they do", he said.
Wiltshire local woman Dawn Sturgess died after inadvertently spraying herself with the Novichok virus which was inside a discarded perfume bottle.
Noted that these cameras allowed us to track the route of Alexander Petrov, and Ruslan Bashirov 3 and 4 March.
Why have no charges been brought for the death of Dawn Sturgess?
"(This) means that if either man travels to a country where an EAW is valid, they will be arrested and face extradition on these charges for which there is no statute of limitations", which means the charges never expire.