The new Equality Bill is set to reveal the extent of the gender pay gap in the UK. The legislation, promised in Labour's 2005 election manifesto, will require firms which employ at least 250 staff to publish details of the average hourly pay of male and female workers by 2013. If too few comply voluntarily, the Government will use legal powers to force them. The Bill will also ban age discrimination outside the workplace and impose a duty on public bodies to address other social inequalities. Ministry for Equality Harriet Harman said the Bill would help to "narrow the gap between rich and poor and make Britain more equal" and rejected claims that it was an unaffordable luxury during the economic downturn. She said: "When times are hard, I think people will feel better if they think we are all in it together. There is no excuse for having unfairness when times are difficult. "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." The Bill is also expected to ban secrecy clauses which prevent staff from disclosing their salaries to colleagues. But British Chambers of Commerce director general David Frost warned that it will delay Britain's emergence from recession and called for a moratorium on new employment law. He is expected to say in a speech later: "The result of this will mean that it will take longer to get out of recession and companies will be loathe to take on more employees. "If we are really serious about helping businesses, about creating jobs, why not have a complete moratorium on new employment legislation for the next three years?" Miles Templeman, director general of the Institute of Directors, also said : "This is a further example of unnecessary regulation at a time when companies, particularly small and medium-sized enterprises, are struggling to survive." But Harman insists it will help end discrimination at work which sees women earn around 20 per cent less than their male colleagues.