Bernadette Cadman, aged 42, who works at HSE’s Manchester office, brought a claim for equal pay, arguing that seniority-based pay systems have a disproportionate impact on women.

Cadman has worked for HSE for 12 years and was promoted to a band 2 inspector in 1996. On checking with personnel she found out that she was being paid less than the average salary of male colleagues in the same grade. The difference in pay was in the order of £5,000 to £7,000 a year.

Cadman’s case was taken up with the support of her union, Prospect, and their solicitors Russell Jones & Walker. Paul Noon, General Secretary of Prospect, said: "This is a big step forward in the continuing battle for equal pay for women. The Court of Appeal has indicated support for our case that it is wrong for employers to discriminate against women over pay on the basis of seniority, without objective justification.

"Although the case still has to go to the ECJ, this is a significant victory for our member and also for other women still paid less than men for the same reason as Cadman. It will have far reaching consequences, particularly for seniority-based public sector pay systems."

Prospect will support Cadman’s case to its final conclusion, said Noon. "We will also be telling civil service departments, agencies and other public bodies that they must modernise pay systems as a matter of urgency to remove potential discrimination. The Government and Treasury have said that they support such modernisation. They now need to put their money where their mouth is and provide the necessary funding."

Bernadette Cadman commented: "Equal pay is a vital issue for women. I am grateful for the support of my union and I am delighted that my case will be referred to the European Court for a decision. This case goes much wider than one person and a good result in Europe will mean that thousands of women are equally valued for the work that they do."

Cadman’s solicitor Edward Cooper, a partner at RJW, said: "This is the most important equal pay claim to be brought in the last 10 years.

"The equal pay act makes pay differences between men and women doing the same job unlawful, unless the pay differential can be shown to be a result of a material difference between their cases. That material difference cannot itself be discriminatory, either directly or indirectly.

"Following a European Court decision it has been understood that length of service in a role can be a justification for increased pay, without the need to examine further whether that length of service criterion is itself discriminatory.

"The Equal Opportunities Commission has shown that in this country, and throughout the EU, the length of service of female workers, taken as a whole, is less than that of male workers, due in large part to female workers’ domestic circumstances and obligations.

"In Mrs Cadman’s case, we argued that it was unlawful to allow for men in a comparable role to be paid more than her solely on the basis of length of service and without any need to show why that was justifiable."