A member of the Women's Labour League from 1908 she became its secretary in 1912. She also edited the League's leaflet, which by 1913 became Labour Woman. When World War I broke out she became a member of the War Emergency Workers' National Committee. In 1916 Phillips was present at the formation of the Standing Joint Committee of Industrial Women's Organisations. Phillips was its secretary between 1917 and 1932. Phillips also served on a number of government committees before a woman had been elected to the country's parliament. The most significant were the Consumer Council of the Ministry of Food and the Women's Advisory Committee of the Ministry of Reconstruction. Unlike prominent suffragettes, her vision was not concentrated upon extending the franchise, she wanted state interventions in the free market to be better informed by considerations of life outside the workplace. As a leader of the Women's Labour League, she described its role as "keeping the Labour Party well informed of the needs of women and providing women with the means of becoming educated in political matters". In this endeavour she provoked about a quarter of a million housewives to take part in the labour movement and helped popularise issues such as equality for women in the workplace, school meals, clinics and playspaces for children, the fundamental value of mothering, a more humanitarian, safety-conscious, approach to the design of homes for ordinary families, and an eradication of needless drudgery and squalour from home life. Speaking on the need for adequate bathing and washing facilities in new housing projects, she remarked: "If Labour councillors will not support us on this demand, we shall have to cry a halt on all municipal housing until we have replaced all Labour men by Labour women". Addressing women in Hartlepool she emphasised, "There is still a lot of educating to do and we are going to begin by educating ourselves". As Chief Woman Officer of the Labour Party she reportedly gave women extra confidence to engage in politics and by 1925 the Women's Section was firmly established. At the 1929 general election, Phillips was elected as Member of Parliament for Sunderland. The 1929 'flapper election' was the first in which women under the age of 30 were eligible to vote. In July 1928, Phillips wrote to all women in the Sunderland constituency, stating that 'FOR WOMEN ESPECIALLY, THIS NEXT ELECTION WHICH WILL TAKE PLACE IN 1929 IS VERY IMPORTANT'. She lost the 1931 election and in 1932 died of stomach cancer, aged 50. Phillips was the first Jewish and thus non-Christian woman MP. Nonetheless, she was also an atheist. In September 2019, a plaque was unveiled at 18 Foyle Street, the site of the Sunderland Labour Party's former Committee Rooms. It reads "Sunderland's first woman MP had an office here 1929-1931. Activist and academic, she lobbied for the rights of woman and working people. The Labour Party's Chief Woman Officer ".
