that it "was a bit of a toss up whether Britain and Germany would fight with or against each other in WWI"? No history that I've read- or primary sources I've seen, support that. Yes, Hitler had reservations about attacking Britain but that doesn't mean it was a two way street- and I've never seen anything that supports that "many British also found it abhorrent to fight against the Germans". Certainly there were those who supported and admired fascist doctrines- think Oswald Mosely, but I think the following Wiki excerpt is quite accurate
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The BUF claimed 50,000 members at one point<2> and the Daily Mail was an early supporter, running the headline "Hurrah for the Blackshirts!"<3>
Despite strong resistance from anti-fascists, including the local Jewish community, the Labour Party, the Independent Labour Party and the Communist Party of Great Britain, the BUF found a following in the East End of London, where in the London County Council elections of March 1937 it obtained reasonably successful results in Bethnal Green, Shoreditch and Limehouse, polling almost 8,000 votes, although none of its candidates was actually elected.<4> However, the BUF never stood in a General Election. Having lost the funding of newspaper magnate Lord Rothermere that it previously enjoyed, at the 1935 General Election the party urged voters to abstain, calling for "Fascism Next Time".<5> There never was a "next time", as the next General Election was not held until July 1945, by which time the Second World War in Europe had ended and fascism was discredited.
Towards the middle of the 1930s, the BUF's violent activities and its alignment with the German Nazi Party began to alienate some middle-class supporters, and membership decreased. At the Olympia rally in London, in 1934, BUF stewards violently ejected anti-fascist disrupters, with one protester claiming to have lost an eye, and this led the Daily Mail to withdraw its support for the movement. The level of violence shown at the rally shocked many, with the effect of turning neutral parties against the BUF and contributing to anti-fascist support. As one observer remarked "I came to the conclusion that Mosley was a political maniac, and that all decent English people must combine to kill his movement".<6> The reaction to the Olympia rally can be illustrated in the growth in British Communist parties from 1935 onwards.<7>
Final years and legacy
With lack of electoral success, the party drew away from mainstream politics and towards extreme antisemitism over 1934-1935, which saw the resignation of members such as Dr. Robert Forgan. Its provocative antisemitic activity in London led to serious, often violent, conflict, most famously at the Battle of Cable Street in October 1936, when over 100,000 anti-Fascists of English, Irish, Jewish and Somali (amongst others) descent successfully prevented the fascists from marching through London's East End.
Membership fell to below 8,000 by the end of 1935. The government was sufficiently concerned, however, to pass the Public Order Act 1936, which banned political uniforms and required police consent for political marches. This act hindered BUF activity, although in the years building up to the war they enjoyed brief success on the back of their "Peace Campaign" to prevent conflict with Germany. In May 1940, the BUF was banned outright by the government, and Mosley, along with 740 other fascists, was interned for much of World War II. After the war, Mosley made several unsuccessful attempts to revive his brand of fascism, notably in the Union Movement.
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http://en.wikipedia.org/wiki/British_Union_of_Fascists