Leigh was born in 1885 and she joined the Women's Social and Political Union (WSPU) in 1906.
On 17 September 1909 she and Charlotte Marsh climbed onto the roof of Bingley Hall in Birmingham to protest at being excluded from a political meeting where the British Prime Minister Asquith was giving a speech. They threw tiles which they levered up with an axe at the Asquith's car and at the police. Leigh was given sentences totaling four months in Winson Green Prison. There she again protested about not being treated as a political prisoner by breaking a window and by going on hunger strike. Leigh was force fed.
On 18 July 1912, in Dublin, she threw a hatchet at Prime Minister Herbert Henry Asquith, hitting instead Irish nationalist leader John Redmond who was injured. Leigh was unhappy with the WSPU, but refused to leave when Emmeline Pankhurst asked for loyalty or for members to leave. She remained loyal as she felt an ownership for the organisation she had helped create.
After Emily Davison was run over by the king's horse at the Derby in 1913, Leigh and Rose Emma Lamartine Yates was at the dying Davison's bedside, and headed a guard of honour for the funeral procession.
World War I precipitated a split between Leigh, Yates and other leading suffragettes with Emmeline Pankhurst. Pankhurst had agreed that the WSPU would suspend its militant campaign for female suffrage and back the government's fight against Germany. Leigh and others disagreed with this policy, and broke away to form the "Suffragettes of the WSPU". The organisation intended to be militant and national but never achieved a large impact. Like the Independent WSPU it was created in 1916. The SWSPU passed a resolution to concentrate on women's suffrage and to not encourage debate about former WSPU leaders.
Simon Webb, author of a book on suffragette terrorism, wrote in a letter to The Guardian that Mary Leigh and other suffragettes set fire to a theatre full of people and bombed it. They were prosecuted for "endangering life".
|Wikimedia Commons has media related to Mary Leigh.|
- Purvis, June. Emmeline Pankhurt: A Biography. Routledge. pp. 109–110. ISBN 978-0-415-23978-3.
- "Starving Suffragist Ill" (PDF). New York Times. 25 August 1912. Retrieved 13 April 2011.
- Crawford, Elizabeth. The Women's Suffrage Movement: A Reference Guide, 1866–1928. Routledge. pp. 338–340. ISBN 978-0-415-23926-4.
- Myall, M. (2004-09-23). Leigh [née Brown], Mary [Marie] (b. 1885, d. in or after 1965), militant suffragette. Oxford Dictionary of National Biography. Retrieved 1 December 2017
- Krista Cowman (15 July 2007). Women of the Right Spirit: Paid Organisers of the Women's Social and Political Union (WSPU), 1904-18. Manchester University Press. p. 190. ISBN 978-0-7190-7002-0.
- Crawford, pp. 340 and 764
- Crawford, Elizabeth (1999). The Women's Suffrage Movement : A Reference Guide, 1866-1928. London: UCL Press. p. 763–764. ISBN 978-1-84142-031-8.