Russia will soon expel British diplomats in retaliation for the UK’s decision to kick out 23 Russian envoys over a chemical attack on Sergei Skripal, a former Russian double agent, Foreign Minister Sergei Lavrov said on Thursday. Britain says Russia is responsible for the poisoning with a Soviet-era Novichok nerve agent of Skripal, 66, and his daughter Yulia, 33. They were found unconscious on March 4 in the city of Salisbury in southern England and remain critically ill in hospital. The Kremlin said the British position was irresponsible and not backed up by evidence. It said Britain would not have to wait long for Russias response. Lavrov was quoted by the official news agency RIA as saying the accusations were unacceptable and that British diplomats would be expelled. But in a series of British media interviews early on Thursday, Foreign Secretary Boris Johnson said the evidence of Russian guilt was "overwhelming" because only Moscow had access to the poison used and a motive for harming Skripal. "There is something in the kind of smug, sarcastic response that were heard from the Russians that to me betokens their fundamental guilt," he told the BBC. "They want to simultaneously deny it and yet at the same time to glory in it." Johnson suggested that "corrupt Russians" who owe their wealth to their ties with President Vladimir Putin could be targeted by British police in retaliation. "What people want to see is some of the very rich people who are directly associated with Vladimir Putin ... whose wealth can be attributed to their relationship with Vladimir Putin, it may be that the law agencies, that the police will be able to put unexplained wealth orders on them, to bring them to justice for their acts of gross corruption," Johnson told BBC. France on Thursday agreed with Britain that Russia was behind the nerve agent attack, President Emmanuel Macrons office said in a statement, adding a united European and transatlantic response was needed. "Since the beginning of the week, the United Kingdom has kept France closely informed of the evidence gathered by British investigators and evidence of Russias responsibility in the attack," Macrons office said in a statement issued after a phone call between the French president and British Prime Minister Theresa May. "I will announce the measures that we are going to take in the coming days," Macron told reporters during a visit to central France.