The sanctions affect 13 Russian nationals and three entities aligned with the Internet Research Agency (IRA), a group that in essence serves as Russia's propaganda arm and is believed by USA intelligence to have been behind divisive online ads released during the election.
Russia has denied any involvement, cast Britain as a post-colonial power unsettled by Brexit, and even suggested London fabricated the attack in an attempt to whip up anti-Russian hysteria.
In a rare joint statement, the leaders of Britain, France, Germany and the USA on Thursday condemned the nerve agent attack on Sergei Skripal and his daughter Yulia as an "assault on United Kingdom sovereignty".
Russia said earlier on Friday it would expel British diplomats in response to British Prime Minister Theresa May's decision to kick out 23 Russians. Russian Federation has said it will reply in kind.
Several Labour legislators have signed a motion declaring support for the Conservative government's view that there is no plausible alternative explanation, other than Russian responsibility, for the attack in the English city of Salisbury.
Britain previously accused Russian Federation of being behind what it has called the "brazen" nerve-agent attack on Sergei Skripal, 66, and his daughter, Yulia, 33, in Salisbury, England, on March 4.More news: Russian Federation alleges U.S. taking actions to stop Trump-Kim Jong-un meeting
But in an unexpected twist, Russian investigators said on Friday they had opened a criminal investigation into the attempted murder of Yulia Skripal and stood ready to co-operate with British authorities.
Foreign Secretary Boris Johnson has reassured Russians that the UK's dispute is specifically with "Putin's Kremlin", claiming it is "overwhelming likely it was his decision to direct the use of a nerve agent" in Britain.
Skripal and his daughter have been critically ill since March 4, when they were found unconscious on a bench. A report Friday in the Telegraph says it was put in the suitcase of Skripal's daughter before she left Russian Federation for Britain to see her father.
During a museum visit in west London alongside his Polish counterpart Jacek Czaputowicz, Johnson said: "We have nothing against the Russians themselves". He wished the Skripals a speedy recovery and said he hopes they can shed light on what happened when they are well.
"Our quarrel is with Putin's Kremlin, and with his decision, and we think it is overwhelmingly likely that it was his decision to direct the use of a nerve agent on the streets of the United Kingdom, on the streets of Europe, for the first time since the second World War", Johnson told reporters in the British capital.
Kremlin spokesman Dmitry Peskov immediately shot back, saying that bringing up Putin in the context of the case was "shocking and unforgivable in terms of diplomatic behavior".