During the 1998 Pay Equity Inquiry in New South Wales, Justice Mary Gaudron made the now oft-quoted statement: “We got equal pay once, then we got it again, and then we got it again, and now we still don’t have it.”

Despite being more than a decade old, the statement stands. And while the debate this week has returned to maternity pay for working women, the issue of pay standards remains. Last week, the Australian Council of Trade Unions launched a community and political campaign calling for government intervention and establishing equal pay for women as a major union priority for 2010.

Recent figures from the Australian Bureau of Statistics show Australian women earned just 82.5% of the average male rate of pay across the country in 2009. On average, a female worker would have earned more in 1985 — and will be $1 million worse off over their lifetimes than their dads, brothers and partners.

These historical differences stem from more than a century of institutionalised wage discrimination against female workers. In the early years of federation, wage levels were based on a male’s need to support his family (established by the famous Harvester Case of 1907).

The first direct intervention into the market for women’s wages occurred in 1912. In the Rural Workers Case, equal pay was granted to female workers in occupations where men could be replaced by female workers on a lower wage. But in female-dominated industries, wages were set at a proportion of the male rate because it was assumed these women were not supporting a family. The female rate was initially set at 66% of the male rate but was lowered to 54% in 1919.

Movements towards some form of equality in wages were made between WWII and the late 1960s. The National Wage Case of 1949-1950 increased the basic female award wage to 75% of the male rate; the International Labour Organisation adopted called for rates of remuneration established without discrimination based on s-x.

The states made the first legislative move: New South Wales took the first tentative steps in 1958 and, with the exception of Victoria, each state followed.  And the real turning point was the federal Equal Pay Cases of 1969 and 1972.

In the 1969 Case, the Commonwealth Conciliation and Arbitration Commission introduced equal pay for equal work, with the objective of bringing federal awards in line with those of the states — but didn’t apply to work usually performed by females. In 1972 the Commission enlarged the concept of “equal pay for equal work” to “equal pay for work of equal value”. In theory, this meant that the sex of an employee would not determine award rates.

Both of these cases had important effects on the Australian labour market. The pay differential between male and female workers narrowed substantially from the early 1970s onwards, as relative award levels for females increased by almost 30% between 1968 and 1977. There was also a significant boost in female employment — it jumped by 15% while total hours worked by females increased by 7%.

But more than 30 years later progress has stalled. Academics point to the high level of male/female labour segmentation in Australia; others the high level of part-time employment of females. Numerous state and federal inquiries have sought to understand and close the continuing wage gap, leading to the establishment of the Equal Opportunity for Women in the Workplace Act in 1999.

The Australian union movement has argued the introduction of WorkChoices by the Howard Government represented a significant setback for women in the workplace, with the gender pay gap widening for the first time in 25 years. Female leaders in unions, business and government have come together to form the Equal Pay Alliance, launched in September last year, with more than 135 organisations taking part.

The current ACTU campaign fights an old battle on new ground. The focus of the ACTU on business practice opens a new front in May Gauldron’s sense of déjà vu.