The government has published legislation that requires employers to reveal the "gender pay gap" between male and female staff.
The Equality Bill, which was a 2005 election manifesto commitment, bans age discrimination outside the workplace and places a duty on public bodies like councils and health authorities to address social inequalities.
Alongside the publication of the Bill, the government is also launching a consultation later today entitled “Equality Bill: Assessing the impact of a multiple discrimination provision”.
The provision for women-only shortlists for political party candidates will be extended until 2030, under the legislation.
Harriet Harman, the minister for equality, told delegates at Welsh Labour's conference at the weekend that it was not fair that women were paid 20 per cent less than men when they made up half the workforce.
"It's pay discrimination and it should not be left to the individual woman to explain - it should be down to the employer to explain and to justify if pay is unequal," she said.
The Bill will also give public authorities a duty to examine how they can narrow the gap between the rich and poor.
Harman added: "I think that when times are hard, fairness is even more important, that people feel that we are all in it together. Equality and fairness is necessary for a meritocracy. It is backward-looking societies which are characterises by rigid hierarchies, women knowing their place and oppression of gays and lesbians."
Firms with more than 250 employees will be "encouraged" to publish details of the average hourly pay for male and female workers by 2013.
If progress has not been made by 2013 on the gender gap, legislation will be brought forward to force disclosure.
The Bill also bans secrecy clauses which prevent staff from disclosing their salaries to colleagues.
Business organisations have protested that the Bill will impose unnecessary bureaucracy on firms struggling in the recession.
But Harman insisted that it will help end discrimination at work which sees women earn around 20 per cent less than their male colleagues.
Speaking on Sky News' Sunday Live, Harman said that she would resist the critics who were saying that the recession was not the time to introduce the legislation.
"There are people who say the quest for equality is a luxury that we should only do in good times and let's put it on the back-burner now," she said.
"But when times are hard, I think people will feel better if they think we are all in it together. I think that's the worst time to be facing unfairness, prejudice and discrimination.
"So I think there is no excuse for having unfairness when times are difficult."
She added: "I think that the economies and societies which will prosper in the future are not those that have rigid hierarchies, where women know their place and where you can't go forward because of the colour of your skin. That's a very backward-looking argument.
"When we look to the future and how we can make Britain stronger and our economy stronger, those societies in the future that are fair and give everybody opportunities and don't have blinkered old-fashioned prejudices - they will be the ones that go forward."
The government hopes not to have to use the law to enforce the equalities legislation once businesses started being more open about what they pay, she said.
Michelle Mitchell, charity director for Age Concern and Help the Aged, continues: "Many politicians and employers have already recognised that a national default retirement age no longer makes sense and the majority of the public want to see it abolished too. The Equality Bill is the perfect opportunity for the Government to end this blatant form of discrimination."
Legislation to be harmonised in the new Act:
* Equal Pay Act 1970;
* Sex Discrimination Act 1975;
* Race Relations Act 1976;
* Disability Discrimination Act 1995;
* Employment Equality (Religion or Belief) Regulations 2003;
* Employment Equality (Sexual Orientation) Regulations 2003;
* Employment Equality (Age) Regulations 2006;
* Equality Act 2006, Part 2;
* Equality Act (Sexual Orientation) Regulations 2007.
Main aims according to the government press release:
1. Introducing a new public sector duty to consider reducing socio-economic inequalities;
2. Putting a new Equality Duty on public bodies;
3. Using public procurement to improve equality;
4. Banning age discrimination outside the workplace;
5. Introducing gender pay reports;
6. Extending the scope to use positive action;
7. Strengthening the powers of employment tribunals;
8. Protecting carers from discrimination;
9. Offering new mothers stronger protection when breastfeeding;
10. Banning discrimination in private clubs; and
11. Strengthening protection from discrimination for disabled people.

Dods Parliamentary Communications Ltd