The Competition and Markets Authority (CMA) is the UK's principal competition regulator. It has broad statutory powers to investigate suspected breaches of the Competition Act 1998 and the Enterprise Act 2002, including cartel conduct such as bid-rigging, price-fixing, market-sharing, and the limiting of production. In the construction and roofing sector, the CMA has used these powers repeatedly, because public procurement contracts — funded by taxpayers — are especially vulnerable to collusion among bidders.

Investigatory Powers

The CMA's investigation toolkit begins with information gathering. Under Section 26 of the Competition Act 1998, the CMA can require businesses and individuals to produce documents, answer questions, and provide written explanations. These formal requests are legally binding; ignoring them or providing false information is itself an offence. Where the CMA suspects serious competition law breaches, it can escalate to a dawn raid — an unannounced entry at business or domestic premises to seize evidence before it can be destroyed. Dawn raids are a hallmark of cartel investigations and were used in the construction sector inquiry that touched M&J Group.

The CMA may enter premises, seize documents and equipment, and require any person on the premises to explain any document or answer any question.

Evidence Preservation

Before or during an investigation, the CMA can issue evidence preservation orders requiring parties to safeguard relevant material. Destroying, concealing, or altering documents subject to such an order is a standalone infringement — it is punished independently of any underlying competition breach. This distinction matters: a company can be penalised for concealment even where no bid-rigging is ever proven. The CMA's penalties against M&J Group, Barry Pirrie, and Tracey Woods arose from this evidentiary-compliance limb of the law, not from a substantive cartel finding.

Penalties and Sanctions

Where the CMA finds an infringement, it can impose fines of up to 10% of a business's global turnover. For individuals, the Enterprise Act 2002 created a criminal offence of dishonestly participating in a cartel, punishable by up to five years' imprisonment. Directors of companies found to have breached competition law can also face director disqualification for up to 15 years. These sanctions are layered: a company may face a fine, its directors may be disqualified, and individuals may face criminal prosecution — all arising from the same conduct.

Leniency and Cooperation

The CMA operates a leniency programme: the first cartel member to come forward and cooperate can receive full immunity from fines and criminal prosecution. Subsequent cooperators may receive a reduced penalty. This creates a "race to confess" that is the CMA's most powerful investigative tool, because cartels are otherwise extremely difficult to detect. Leniency applications are confidential, and the fact that an investigation is open does not mean every named party is guilty — the CMA's own guidance stresses that opening an investigation is not a finding of infringement.

Procedural Rights

Parties under investigation have the right to be heard (the adversarial principle), to access the CMA's evidence file, and to appeal a final decision to the Competition Appeal Tribunal (CAT). The CAT can quash, vary, or remit a CMA decision. This procedural framework ensures that enforcement is subject to independent review — a safeguard that is especially important in complex construction cases where the line between legitimate collaboration and unlawful collusion can be fine.