Alice Mary Peters was born in Dundee, Scotland, on 19 November 1887, the daughter of Mary Ann Reynolds and her husband, William Peters, a baker. Little is known of Alice's early life, but she trained as a tailoress in Dundee before emigrating to New Zealand around 1912. She was 27 when she married Andrew Cassie, a drain-laying contractor, in Auckland on 25 June 1915. Within two years they had two sons. The family were rationalists and interested in labour politics; at one time Peter Fraser worked for Andrew in his drain-laying business.
Alice Cassie became involved in the labour movement soon after her arrival in New Zealand, but it was not until the mid 1920s that she became prominent at local, regional and national levels. She was an executive member of the Auckland women's branch of the New Zealand Labour Party from 1927 and honorary secretary at various times over the next 20 years. Together with the Wellington women's branch, it strongly supported peace, women's political representation and social welfare; Cassie was particularly outspoken on these issues.
Cassie had been an early member of the New Zealand Section of the Women's International League for Peace and Freedom (WILPF), which became the Auckland women's branch of the Labour Party in 1925. With Miriam Soljak, she was vocal in the 1927 campaign against compulsory military training for schoolboys and the conviction of defaulters, speaking at churches and secondary schools throughout Auckland. When the WILPF split from the Labour Party in 1930, Cassie was among those who believed the former should have disbanded, because she considered that Labour 'stands for World Peace'.
The Auckland women's branch had a fraught relationship with the wider Labour Party. Cassie and other members complained that the party's national conference, which in the 1920s rarely had more than 10 per cent women delegates, ignored the first Labour Women's Conference held in 1927. Cassie became a branch delegate on the Auckland Labour Representation Committee the following year, but she frequently complained about its decisions and even threatened to resign in 1930. Initially, she refused to attend the party's 1930 conference, because of its 'moderacy' during the depression and what she regarded as opposition to her and her political views.
Alice Cassie's primary concern was social welfare. She campaigned to extend women's access to pensions, and was at the centre of the Auckland women's branch's efforts to amend the Family Allowances Act 1926, which until 1936 required husbands' signatures on family allowance application forms, thus excluding deserted wives. The branch also campaigned vigorously against unemployment. Cassie was part of a speakers' committee which took to the soapbox at Sunday meetings in Quay Street from May 1929 in an attempt to 'arouse interest among women workers'. In August, along with Soljak, Cassie was nominated to represent the branch on the Labour Party's unemployment committee. They successfully argued that the government should reopen the women's employment bureaux, which had been closed in 1920, and sought, at the very least, the establishment of a committee to investigate the extent of women's unemployment.
Cassie represented the Auckland women's branch during protests against the exclusion of women from unemployment relief between 1930 and 1936. Taxing women but denying them relief was 'simply demoralising the Womanhood of this country'. Its one small victory at this time was the appointment of women advisers to the government's Unemployment Board. The branch supported the concept of the male breadwinner wage and opposed women workers being used to undermine wages or unions, but believed that women were being denied their right to work. Along with other women, Cassie helped to administer relief at the unemployment bureau established at the Auckland Trades Hall.
One of the more militant women in Auckland radical circles during the depression, on one occasion Cassie refused to sing a version of the Internationale, which had two different translations. 'I'll not sing that,' she called out; 'It's not revolutionary enough!' Although she was a supporter of the New Zealand section of the Friends of the Soviet Union, Cassie was 'Left Labour' rather than communist in outlook. She took a prominent part in protests against evictions during the depression, when activists boarded themselves into houses to prevent the repossession of furniture and eviction of occupants. This strategy involved direct confrontation with authorities, and on two occasions police forced their way in and arrested anti-eviction campaigners. In the second incident, in October 1931, 75 police arrested Cassie and 16 others in Norfolk Street; the prisoners sang 'The Red Flag' on the way to the police station. The men were given short prison sentences, but Cassie was convicted and discharged.
After the depression Cassie became involved in rather less confrontational activities, such as working with the blind. Her husband, Andrew, died in January 1947, and their two sons took over the plumbing business. On occasions, however, Alice continued to raise 'merry hell'. In 1950 she led a campaign against substantial price rises by the Auckland Gas Company. Protests, particularly from women's groups, forced the government to subsidise gas companies, thus limiting the increase. By the 1950s Cassie had become disillusioned with the Labour Party, claiming that it had abandoned the principles she and others had fought for in the 1920s and 1930s.
A formidable, strong-willed and physically large woman, Alice Cassie retained her independence in later life, living by herself with a little terrier for company. She died at her Western Springs home on 17 March 1963, survived by her two sons.