The Competition and Markets Authority secured the ban after investigators discovered that two materials suppliers had been involved in price-fixing meetings for seven years from 2006.

Derbyshire-based Stanton Bonna Concrete and Somerset-based CPM Group admitted breaking competition law by taking part in a cartel.

A third company is also still under investigation having not entered into settlement.

Philip Stacey and Robert Smillie were directors at CPM throughout the period of the alleged cartel activity, during which time the company was one of the leading players in the market.

The CMA has secured legally binding undertakings from the former directors, which disqualify them as directors and prevent them from being involved in the management of any company based in England, Scotland and Wales.

Stacey has been disqualified for 7 years and 6 months, and Smillie has been disqualified for 6 years and 6 months.