UK Construction and Law

The competition regulator puts bid rigging in public procurement at 1bn to 3.5bn pounds a year and asks for losing bids to be kept

By Staff Writer  |  9 September 2026

Two reports published on 8 September say most of the regulator's bid rigging cases have been in construction, that public sector construction spending is 41 billion pounds a year, and that the data needed to screen tenders at scale is not collected. The chief executive wants bid rigging named as a priority in the National Procurement Policy Statement and every losing bid retained in machine readable form.

The Competition and Markets Authority published the two papers on Monday and presented them to four all party parliamentary groups the same day. The first closes two years of work across civil engineering, cloud computing, defence and the scale-up challenge. The second makes the case for what the authority calls urgent action on bid rigging.

What the authority says it knows

The bid rigging paper starts from the 400 billion pounds the public sector spends each year with private suppliers. Research cited from the OECD puts the price effect of bid rigging at 20 per cent or more, and fewer than one fifth of cartels are ever detected. On a conservative assumption that 2 per cent of public procurement is affected, taxpayers overpay by 1 billion pounds a year; on still conservative estimates the figure rises to 3.5 billion.

Using conservative assumptions of prevalence, the CMA estimates that taxpayers could be overpaying suppliers by between £1 billion and £3.5bn every year. That is desperately needed money, which goes directly from stretched departmental budgets into the pockets of colluding firms.

Sarah Cardell, Chief Executive, Competition and Markets Authority, 8 September 2026

Since 2014 the authority has completed seven bid rigging cases, imposing more than 129 million pounds in fines on 31 companies. More than half involved public procurement and most involved construction, which the paper puts at 41 billion pounds of public spending a year.

Two construction case studies

The first case study is the 2023 demolition and asbestos removal decision, in which ten firms, Erith Contractors and Keltbray among them, were fined more than 60 million pounds and four individuals were disqualified as directors for nearly 25 years in total. The conduct ran from January 2013 to June 2018 across 19 contracts worth more than 150 million pounds, with sites including the Metropolitan Police training college and the former Bow Street Magistrates Court. One firm sent a rival its own pricing document with the instruction to "go some 8% to 10% above this", and five of the firms arranged compensation for the designated losers, in one instance above 500,000 pounds, hidden behind false invoices.

The second is the galvanised steel water tank cartel, fined more than 2.6 million pounds in 2016: four suppliers of the tanks used in schools and hospitals met in secret from 2005 to 2012, marked customers A, B or C according to who would have them, and fixed prices.

The live investigation matters more to anyone bidding this autumn. In December 2024 the authority opened a case into suspected bid rigging in the supply of roofing and other construction services to schools under the Department for Education's Condition Improvement Fund, and in January 2026 it added parties and widened the scope to other public and private bodies. The investigation is ongoing and no infringement has been found.

What is asked for

The paper's central complaint is data. The authority's own Bid Rigging Intelligence Tool has been run in pilots with government departments and has produced live leads, but the information it needs, above all the losing bids, is not routinely collected in a consistent, centralised or machine readable form. Spain, Portugal, Korea and Brazil mandate collection of that data; Germany and Ireland are legislating for it.

Three recommendations follow. Government should make preventing, detecting and deterring bid rigging an explicit priority in the National Procurement Policy Statement and related guidance. It should scale screening across central government and the wider public sector, mandating the collection and retention of all bid level information in a form that can be analysed. And it should evaluate the results transparently, without publishing methods that would help firms evade them.

The paper also restates the consequence that already exists in law. Under the Procurement Act 2023 a supplier involved in bid rigging or other cartel conduct risks mandatory exclusion from individual procurements and entry on the central debarment list, which shuts it out of all public contracts for up to five years. Contracting authorities may ask the authority for information relevant to exclusion and self-cleaning assessments.

The civil engineering strand of the first paper is the market study on road and rail infrastructure, some 19 billion pounds of public spend a year, which found the problem was not a shortage of suppliers but fragmented accountability and uncertain pipelines. The message to public clients from both papers is the same: keep the pipeline visible, keep the bids, and expect them to be read by a machine.