Oleg Lyalin, a former Soviet

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 agent

Espionage

Espionage or spying involves an individual obtaining information that is considered secret or confidential without the permission of the holder of the information. Espionage is inherently clandestine, lest the legitimate holder of the information change plans or take other countermeasures once it...

 who defected

Defection

In politics, a defector is a person who gives up allegiance to one state or political entity in exchange for allegiance to another. More broadly, it involves abandoning a person, cause or doctrine to whom or to which one is bound by some tie, as of allegiance or duty.This term is also applied,...

 from the KGB

KGB

The KGB was the commonly used acronym for the . It was the national security agency of the Soviet Union from 1954 until 1991, and was the premier internal security, intelligence, and secret police organization during that time.The State Security Agency of the Republic of Belarus currently uses the...

. His defection led to the expulsion of 105 Soviet officials suspected as being Soviet spies from Britain

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 on 25 September 1971.

Mr. Lyalin was sent by the KGB to London

London

London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

 in the 1960s, posing as an official with the Soviet Trade Delegation.

His defection came about after he was arrested in London by Policeman Charles Shearer for drunk driving. His bail of £50 was paid by the Russian Trade Delegation but he was taken to a safe house by MI5

MI5

The Security Service, commonly known as MI5 , is the United Kingdom's internal counter-intelligence and security agency and is part of its core intelligence machinery alongside the Secret Intelligence Service focused on foreign threats, Government Communications Headquarters and the Defence...

. He offered to disclose information about KGB activities in exchange for a new life with his Russian secretary, Irina Teplyakova, with whom he had begun an affair.

The expulsion of 105 officials was the single biggest action taken against the Soviet Union by any western government. Sir Alec Douglas-Home, foreign secretary at the time, was accused by the Labour

Labour Party (UK)

The Labour Party is a centre-left democratic socialist party in the United Kingdom. It surpassed the Liberal Party in general elections during the early 1920s, forming minority governments under Ramsay MacDonald in 1924 and 1929-1931. The party was in a wartime coalition from 1940 to 1945, after...

opposition of over-reaction.

Lyalin was given a new identity by MI5 and remained in hiding until his death on 12 February 1995.