A senior MP has warned of stricter diversity reporting rules for private sector employers when the Equality Bill is officially set out in the Queen's Speech next month.
Maria Eagle, deputy minister for women and equality, said increasing company transparency was on the agenda.
The first draft of the Equality Bill was tabled by equalities minister Harriet Harman in June, and included measures to force public bodies to publish statistics on their gender pay gaps and numbers of ethnic minority and disabled workers.
But Eagle told delegates at a conference hosted by the Age and Employers Network: "We intend to introduce a new equality duty on the public sector, and to increase the requirements that we have for transparency, particularly in the private sector.
"We can say, 'well look, here are the figures, you only have 10% women and no older workers, what is going on in your firm?' - and that has the capacity to really shine a light on to employment practices," she said.
The Government Equalities Office said it could not rule out requirements for the private sector in the Equality Bill.
"There are many different measures with different effects planned, all with the aim of encouraging more transparency in the private sector," a spokeswoman said.