British Foreign Secretary Boris Johnson said Russia targeted Skripal a former Russian intelligence officer convicted of spying for Britain a to make it clear that those who defy the Russian state deserve to "choke on their own 30 pieces of silver".
"All the steps will be well thought out", he told reporters.
Lavrov said Moscow had stopped paying attention to Britain over the spy poisoning allegations.
Russian Federation has denied the accusations and has accused Britain of fabricating the story.
Peter Wilson told reporters that Russian Federation, which President Vladimir Putin said in 2017 had destroyed all its chemical weapons under OPCW supervision, has in fact "failed for many years" to fully disclose its chemical weapons program.
He did not provide further details.
The expulsion of the diplomats, who have been given one week to leave the country, is the largest since 31 were ordered out in 1985 after double agent Oleg Gordievsky defected.
The crisis unravelled in the thick of a Russian presidential campaign, with Putin expected to win a fourth Kremlin term on Sunday.
"We have nothing against the Russians themselves".
Relations between London and Moscow have crashed to a post-Cold War low over the attack, the first known offensive use of a nerve agent in Europe since World War Two.
The sensational claims were made last night as agents continue to investigate last week's mysterious attempted murder. Russian Federation denies involvement and says it has no information on the case.
"We don't care about the fate of a traitor", said Colonel General Ladygin.
The two are still undergoing treatment to recover from the deadly Russian nerve agent.
"It is an assault on the United Kingdom's sovereignty and any such use by a state party is a clear violation of the Chemical Weapons Convention and a breach of worldwide law", the statement said.
"What people want to see is some of the very rich people. 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", he said.
She will meet members of the public, businesses and emergency services personnel in the southwestern English city of Salisbury, where Sergei Skripal and his daughter were poisoned on March 4.
Earlier this week, outgoing Secretary of State Rex Tillerson called the nerve agent attack "a really egregious act" that appears to have "clearly" come from Russian Federation.
More: Who is Sergei Skripal?
Mirzaynov was sacked after revealing the existence of Moscow's classified programme to produce Novichok and now lives in the United States.
The UK is to brief the UN Security Council on the poisoning of a former double agent from Russian Federation later, the Foreign Office has said.
The ministry said Moscow's measures were a response to what it called Britain's "provocative actions and groundless accusations".