He joined the
British Union of Fascists in 1933 and soon rose to the post of Director of Policy. There, he became the leading ideological light in the party and a close associate of
Oswald Mosley and
Neil Francis Hawkins. In that position, he produced his seminal work
The Corporate State (March 1935, republished as
The Coming Corporate State in January 1937) in which he set out the vision of a BUF government in Britain. Thomson envisaged the formation of 20
corporations, each controlling a specific sector of the economy. The corporations would be further divided up to cover each individual industry and would also feed into a National Corporation, which would effectively form the government. Corporations would have equal representation for employers, workers and consumers, with elections to the corporations taking the place of existing political activity. In 1935, he was sent to his native Scotland on a speaking tour designed to present the fascist message, but most of his engagements were disrupted by communist hecklers, including one at
Aberdeen in which an extended chorus of
The Internationale from the crowd effectively silenced the BUF speakers. Thomson became a leading figure in the BUF and in 1937 represented the party in municipal elections in
Bethnal Green (SW). He won 23.17% of the votes and finished ahead of the
Liberal candidates. Although he was not elected, the result marked a good total for the BUF. His status in the party now assured, Thomson became editor of the party weekly,
Action, in 1939. An important figure in the BUF, he served for a time as Mosley's representative to Germany, a role in which he was closely watched by
MI5. He shared with the
Nazis a strong
anti-Semitism and was generally noted as an admirer of
Nazi Germany. He was part of BUF delegation that attended the 1933
Nuremberg Rally. He made a total of five extended trips to Nazi Germany. Despite being one of the public faces of the BUF, he had actually been interviewed by
The Jewish Chronicle in 1934 and had told the newspaper that the group had no specific enmity towards the Jews. Thomson also had loose connections to hardline
Revisionist Zionism activist
Wolfgang von Weisl, but they were curtailed after von Weisl's superior,
Ze'ev Jabotinsky, told him to break off relations. Mosley admired Thomson for his intellect and would later describe him as an "honest man and devoted patriot" but was also known to criticise him privately as something of a "yes-man". In 1937, Thomson wrote that the
British left had enforced "specifically Anglo-Saxon democratic methods of parliamentary governance" upon Ireland to which it was "entirely foreign and distasteful". Thomson also believed that a
United Ireland would occur under fascism, an ideology that was less foreign to the "
native Celtic culture". After the outbreak of war, Thomson devised a plan to attack the
Nordic League as "Nazi traitors" in the hope of establishing the BUF's patriotic credentials, but that came to nothing and actually ran alongside attempts by Francis Hawkins to establish BUF control over the League. Along with most of the other leading members of the BUF, Thomson was detained under
Defence Regulation 18B in May 1940 and interned for much of the
Second World War. He spent his entire jail spell in
Brixton Prison, rather than the prison camp on the
Isle of Man, which was generally more favourable, until his release in 1944. Thomson reacted badly to his spell in detention and suffered a
nervous breakdown during his incarceration. He was released after he had been moved to a camp on the Isle of Man in September 1944. ==Union Movement==