The Conservatives called on the government to give a “clear message” to business about how it intended to use the state’s £160bn-a-year ($307bn) spending power to tackle discrimination in the private sector. The opposition party’s intervention came after the FT revealed on Friday senior ministers were split over the issue.

Alistair Darling, the chancellor, is resisting pressure by Harriet Harman, the Labour deputy leader and minister for equality, to change procurement rules to improve gender and racial equality in the 30 per cent of companies that sell goods and services to the state.