A Downing Street spokesman said:
The Prime Minister spoke to President Macron of France to update him on the latest situation regarding the incident in Salisbury on 4 March.
She outlined the conclusion reached by the Government that it was highly likely that Russia was responsible for the act against Sergei and Yulia Skripal.
They discussed the wide pattern of aggressive Russian behaviour and agreed that it would be important to continue to act in concert with allies to address it.
President Macron condemned the attack and offered his solidarity with the UK.
They agreed that the French and British governments should coordinate closely as the investigation developed and following Russia’s response.
Link: Press release: PM call with President Macron: 12 March
Source: Gov Press Releases