Equity and other causes
In 1929, at the age of seventeen, he became a founding member of British Equity, the actors' union, and would be intricately involved with it for the rest of his professional life.
He served on its council from 1949 and was three times its vice president from 1963 to 1965, 1975 to 1977 and again from 1980 to 1982.
Goring's relationship with his union was fraught with conflict and, as an influential and conservative member of the union he waged battles in the 1970s with such left-leaning members as the Redgraves: Vanessa and her brother Corin. He did not want union funds being contributed to causes such as the Miner's Strike fund as he viewed that as sacrificing its neutrality. He believed that, above all, the union's focus should always be on the welfare of its members and that it should not get involved in political causes.
As the vanguard of the conservative faction in Equity (Act for Equity), he spent years battling the Redgraves and their Workers Revolutionary Party supporters for control of the union. Corin Redgrave was known to refer to him insultingly as "Herr Goring".
These fights became increasingly vitriolic and quite bitter at times, often waged through the editorial pages of The Times and The Stage newspapers. Marius was a frequent writer of Letters to the Editor of The Times and other newspapers about union matters and on a number of other subjects on which he had an opinion.
Marius was prepared to fight strenuously for any cause he believed in, often taking court action and putting his financial security on the line, particularly in his battles with Equity. He claimed his doggedness was inherited from his father. He also seems to have been profoundly influenced in his fighting determination by his work in propaganda during WW2, believing that "the best way to win round an enemy is to infiltrate their culture, rather than isolate it". And he also firmly believed that "Art can only flourish when it is apolitical". Thus, his belief that Equity should be strictly neutral in political terms and his firm resistance to the restrictions imposed on actors working in South Africa during apartheid and Equity bans on TV & radio programmes being sold there. See interview with Marius ("An old trouper who fights on for the truth") below.
He took his union to litigation on three occasions. In the longest running case, regarding the issue of the supremacy of a referendum to decide Equity rules, he took it as far as the House of Lords in 1978 and won his case.
However, in 1992, he unsuccessfully sought to end the restriction on the sale of radio and television programmes to apartheid South Africa. This particular litigation nearly bankrupted him, due to the heavy amount of court costs (estimated at the time to be up to £180000). He had even put up the deeds of his house as surety for his legal costs for the earlier court case that went to the House of Lords.
Marius was also a tireless campaigner to save theatres throughout the country from being closed down or demolished. He spearheaded several campaigns with Save London's Theatres, including the Shaftesbury, taking legal action in his own name to prevent it from being gutted. He also worked to save others such as the Lyceum, the Grand Theatre Blackpool and Wilton's Music Hall.
Saving the Shaftesbury was particularly important to him as it was where he had had his West End debut in 1934 in 'The Voysey Inheritance'.