Question: What symbol did Oswald Mosley's 1930s British Union of Fascists use, and his later groups the Union Movement and National Party of Europe?

Context paragraphs:
Flash and Circle: The Flash and Circle is the second symbol used by the British Union of Fascists (BUF) and its best known symbol.  (The BUF had briefly used the fasces of Mussolini's fascists.) It was chosen to represent "action within unity".  Oswald Mosley's post-war group the Union Movement and his National Party of Europe initiative also used this symbol.

Oswald Mosley: Sir Oswald Ernald Mosley, 6th Baronet of Ancoats ( ; 16 November 1896 – 3 December 1980) was a British politician who rose to fame in the 1920s as a Member of Parliament and later in the 1930s became leader of the British Union of Fascists (BUF).

Gary Raikes: Gary Raikes (born 10 August 1958) is the leader of the New British Union, a fascist revival of Sir Oswald Mosley's British Union of Fascists.  He was previously the leader in Scotland of the British National Party and then Britain First.

43 Group: The 43 Group was an English anti-fascist group set up by Jewish ex-servicemen after World War II.  They did this when, upon returning to London, they encountered British fascist organisations such as Jeffrey Hamm's British League of Ex-Servicemen and later Oswald Mosley's new fascist party, the Union Movement.  The activities of these fascist groups included antisemitic speeches in public places, and from the rank-and-file fascists, violent attacks on London Jews and Jewish property.  Group members broke up far-right meetings, infiltrated fascist groups, and attacked the fascists in street fighting.

Union Movement: The Union Movement was a far-right political party founded in Britain by Oswald Mosley.  Where Mosley had been associated with a peculiarly British form of fascism, the Union Movement attempted to redefine the concept by stressing the importance of developing a European nationalism rather than narrower country-based nationalisms.  The UM has therefore been characterized as an attempt by Mosley to start again in his political life by embracing more democratic and international policies, than those with which he had been associated.

British Union of Fascists: The British Union of Fascists, or BUF, was a fascist political party in the United Kingdom formed in 1932 by Oswald Mosley.  It changed its name to the "British Union of Fascists and National Socialists" in 1936 and, in 1937, to "British Union".  It was finally disbanded in 1940 after it was proscribed by the British government, following the start of the Second World War.

Friends of Oswald Mosley: The Friends of Oswald Mosley (FOM) is the last vestige of Oswald Mosley's British Union of Fascists (BUF) and its successors the Union Movement and the Action party.  Their motto is "The spirit lives ... the rest will follow".  The group is not politically active but has described itself as "pro-Islam, pro-EU, against US global supremacy, anti-capitalist, anti-state socialism, [and] pro-syndicalism".

League of Empire Loyalists: The League of Empire Loyalists (LEL) was a British pressure group (also called a "ginger group" in Britain and the Commonwealth of Nations), established in 1954.  Its ostensible purpose was to stop the dissolution of the British Empire, though some critics charged it with being an attempt to re-found the British Union of Fascists.  The League was a small group of current or former members of the Conservative Party led by Arthur K. Chesterton, a former leading figure in the British Union of Fascists, who had served under Sir Oswald Mosley.  The League found support from some Conservative Party members, although it was disliked very much by the leadership.

The Blackshirt: The Blackshirt was the official newspaper of Oswald Mosley's British Union of Fascists (BUF).  The paper first appeared in 1933.  From June 1939 it became the "British Union News".  It ceased the same year.  The paper also incorporated the short-lived "The Fascist Week" (1933-34).

John Warburton (fascist): John Warburton (30 April 1919 – 26 August 2004) was an English fascist and press photographer.  He was an assistant district leader for the Clapham branch of Oswald Mosley's British Union of Fascists (BUF) before the Second World War, and afterwards was a key member of the Union Movement, the founder editor of "Comrade", and the senior Council member of Friends of Oswald Mosley.

Supporting paragraphs: Flash and Circle Oswald Mosley
Answer: Flash and Circle