In 1920, the family moved to Auckland and Soljak joined the Auckland Women's Political League, which five years later became the Auckland women's branch of the
New Zealand Labour Party. Soljak led a public fight, alongside
Elizabeth McCombs, against the nationality laws, speaking to Parliament and publishing articles in the local papers on the unfairness of the legislation. With the break-up of the Austrian Empire, Peter chose to align his nationality with the
Kingdom of Serbs, Croats and Slovenes, later Yugoslavia, in 1922. In 1923, New Zealand adopted the British nationality scheme, which clearly specified that New Zealand women who married foreign men automatically lost their nationality upon marriage. Working with allies like
Emily Gibson and
Peter Fraser, Soljak pressed for legislation for women to have independent nationality. Fraser introduced a bill in 1927, but it was unsuccessful. In 1928, Peter Soljak naturalised, and through his action Soljak regained her British nationality under an amendment passed in 1935, but only while in New Zealand. When travelling abroad, she had to use a passport which was marked "New Zealand born, wife of an alien, now naturalised" and regularly register with the police. From 1926, Soljak worked on women's issues. She fought for women to receive
unemployment benefits, as politicians ignored their
homelessness and their need to work. In 1931, she worked on the Auckland Unemployed Women's Emergency Committee, but resigned when she realised there were no funds to help women and that their actions would only be to compile a registry of unemployed women. Because of the perception that many Māori women participated in
prostitution, Soljak pressed for training to combat their economic hardships and the social ostracism they experienced in the workplace. She stressed that Māori women and girls had civil rights and should be able to choose their own employment and be free of exploitation. She pointed out that Māori women often had to take whatever work they could find. This was borne out in an inquiry undertaken by the Labour Department at the insistence of the Akarana Maori Association, which found few instances of immorality among Maori girls and women, but noted they had difficulty earning enough to provide for themselves and their families. She suggested that hostels be established to train Māori women in child care, domestic service, and nursing. Soljak was involved in the
pacifist movement, as well as advocating for
sex education and programmes to address maternal and child mortality, child welfare, and payments to mothers to recognise their contributions to the nation through raising children. She began working as a
freelance journalist and was a sought-after public speaker, though her style was hard-hitting and confrontational. In 1928, Soljak was elected president of the Auckland women's branch of the Labour Party and re-elected to the post in 1929. The Soljaks separated in 1929, primarily because Peter did not agree with her radical politics and the people with whom she was associating. The following year, she sought a legal separation, but Peter refused to agree, denying Soljak
alimony or
child maintenance. Working with the
Women's International League for Peace and Freedom between 1930 and 1931, she led an initiative to assist women in
Samoa. She condemned the suppression of Samoa's pro-independence
Mau movement in 1930, and was at odds with the Labour Party hierarchy over the issue. After she wrote an article in May, which was published in the
Samoa Guardian protesting searches of the homes of independence leaders, she was ousted from the women's branch of the Labour Party. She then aligned with the
Communist Party of New Zealand and joined other radical organisations. After being counselled by a priest that family size could be controlled by abstinence, Soljak left the Catholic church and began campaigning for women to be able to gain access to
contraception and
family planning. Using the
pen name "Zealandia", she wrote a series of articles for
The New Zealand Herald on the topic and attended a
Wellington conference in 1934, advocating for birth control. After the conference, she helped found the Sex Hygiene and Birth Regulation Society, renamed the New Zealand Family Planning Association in 1940. In 1935, Soljak led a deputation of members of the Women Workers' Movement to the Prime Minister's office to demand changes to the Women's Unemployment Committees. In the manifesto she presented were demands to disband the committees and terminate the current leadership replacing them with labour bureaux for women, which would be run by women; for government employment placement services for women; for payments to elders, the infirm, and widows; and revised policies concerning separated wives of men who were obtaining relief subsidies. Under the sponsorship of the Women's International League for Peace and Freedom, Soljak attended a Commonwealth women's conference in London (1936–37), where presentations covered such topics as the lack of equal rights for women, peace and social initiatives, trafficking, and women's nationality and immigration rights. She presented a talk to the conference on women's nationality issues in New Zealand. Soljak was finally awarded family maintenance in 1936, but during her trip abroad, Peter attempted to terminate the payments. In 1938, she filed for divorce and was granted a
decree nisi, and the divorce was finalised in 1939. Soljak found that she was still classed as a
foreign national, despite her New Zealand birth and the termination of her marriage, as the law had no provisions for a woman to recover her nationality lost upon marriage. When the
Social Security Act was passed in 1938, she wrote an article in
Women Today criticising the fact that though the act entitled single women workers to an unemployment benefit, it paid married women's benefits to their husbands. Soljak joined the
New Zealand Rationalist Association in 1940 and in 1941 was elected to serve on the executive committee. The organisation protested the government's treatment of
conscientious objectors. That year she continued her campaign against the nationality law, speaking on behalf of the
United Women's Movement delegation to the
Minister of Internal Affairs. She pointed out that women should have their own nationality and that the current law also impacted the nationality of their children. Soljak continued to campaign throughout the war on behalf of the United Women's Movement, serving as its treasurer in 1944, and the Women's International League for Peace and Freedom. She pressed for adequate housing for families, as most of the available units had been given to soldiers; for not allowing children's protection to lose focus because of attention to the war effort; and for peace initiatives. At the end of
World War II, she retired from public life to look after her son Paul, who had been wounded in the war. They lived in
Point Chevalier. In 1946, Soljak's nationality was restored, when the New Zealand nationality law was finally revised to grant women individual nationality. In the letter from the Internal Affairs Minister, signed by under-secretary
Joe Heenan, which responded to her request for restoration of her nationality, he stated, "you are deemed never to have lost your British nationality". Eventually, she rejoined the Labour Party and was given a gold badge of service for her work over many years. ==Death and legacy==