of her own committed delegates at the 1976 Progressive Conservative leadership election failed to vote for her, a loss of support which many commentators attributed to sexism. Four women — Deborah Grey, Nycole Turmel, and Rona Ambrose, Candice Bergen — have served as Leader of the Opposition. All of the women served as interim leaders of their parties during leadership campaigns; however, Grey was considered only an acting Leader of the Opposition. Four other women have served as leaders of political parties in the House of Commons: Alexa McDonough, who succeeded McLaughlin as leader of the New Democratic Party in 1995; Elsie Wayne, who served as interim leader of the Progressive Conservatives in 1998; Elizabeth May, who entered the House of Commons in the 2011 election as the leader and first elected MP of the Green Party; and Candice Bergen, who served as interim leader of the Conservative Party of Canada following the resignation of Erin O'Toole. Two smaller political parties which currently do not hold any seats in the House of Commons are also led by women: Communist Party of Canada (Marxist-Leninist) – Anna Di Carlo Animal Alliance Environment Voters Party of Canada – Liz White This dearth of women in political leadership may, in some ways, be attributable to women's general exclusion from important cabinet positions that are seen as stepping stones to leadership. Women were largely excluded from Canadian cabinets until the 1970s. Only in rare instances do women comprise a significant proportion of Canadian cabinets, as in the case of then-Ontario Premier Bob Rae's first cabinet in 1990, in which 11 of 26 ministers were women. As of July 2013, the Harper Cabinet had 11 female ministers in a cabinet of 39, though most held minor portfolios; in October 2015, Justin Trudeau became the first prime minister to appoint a fully gender-balanced cabinet with equal numbers of both men and women. Senate Although women gained the right to stand for election to the House of Commons in 1918, women did not have the right to be appointed to the Senate of Canada until 1929, when Edwards v Canada (AG) (commonly known as the Persons Case) was decided. The following year, Cairine Wilson was appointed as the first woman to sit in the Senate. In 1955, Wilson achieved another first, becoming the first woman to become Deputy Speaker of the Senate. The first female Speaker of the