Following several high-profile investigations, the Competition and Markets Authority (“CMA”) has indicated that bid-rigging in public sector procurement will be a focus for future competition enforcement activity. In this article, we discuss how anti-competitive conduct is treated under the UK’s Procurement Act 2023 and why it is so important for suppliers to stay on top of competition law compliance.
Bid-rigging risks in public sector contracting have gained the attention of the CMA. Bid-rigging involves businesses colluding in public sector tenders. This can take many forms including:
- bid rotation (including where firms agree to share a market between them by agreeing to bid in turns);
- bid suppression (such as agreeing not to bid); and
- cover pricing (for example, to artificially raise a tender price to make other bids appear better value).
The starting point is that this amounts to anti-competitive behaviour in breach of competition law. OECD research suggests that bid-rigging can inflate prices by up to 20% and the CMA has recently announced measures which raise the possibility of further enforcement. It says that bid-rigging in public procurement is an area in which it will apply new enforcement techniques, using AI and other data science tools to scan bidding data for signs of unlawful activity.
The CMA’s public statements reflect its wider messaging about its priorities and recognition that public procurement is one of the main ways that the U.K. Government can realise its ambition of economic growth. The messaging from the competition authority is that procurement should boost the UK’s competitiveness – by building supply chain resilience and providing a vital stepping stone for scaling up high-potential firms.
This is undermined where bid-rigging activity takes place.
All of this points to an appetite for more enforcement activity. It is essential that suppliers understand how competition rules interplay with procurement law and the consequences of being found to have failed to comply with them. The consequences across the procurement and competition law regimes are wide-ranging.
Bid-rigging: recent announcements and investigations
At the end of 2025, the CMA published a case study on “lessons learned” from a case which concluded (in 2023) with 10 construction companies being fined nearly £60m for rigging bids for demolition and asbestos removal contracts. The companies had colluded to submit bids that were deliberately designed to lose, such that the winning supplier did not face genuine competition for the bid.
The CMA also has an ongoing investigation into suspected anti-competitive bid-rigging in relation to the supply of roofing and other construction services to schools which received public funding for these services. This was launched in 2024 with "dawn raids" and was recently broadened in scope, with more parties added.
Both in its draft annual plan and in a response (which it gave in September 2025) to the Cabinet Office’s consultation on public procurement, the CMA has indicated its intention to use data science tools for the purposes of detecting bid-rigging in public procurements. At the start of 2025, Sarah Cardell said that the CMA was trialling the use of these tools, said to be backed by artificial intelligence.
The CMA names the approach in Spain as a source of inspiration. The Comision Nacional de los Mercados (“CNMC”) appears to have had success deploying data analysis techniques for detecting irregularities in bidding for public contracts and has been helped by the introduction of a procurement platform which has allowed it to gather data on losing as well as winning bids.
The success of the CMA’s efforts in this area will be influenced by the quality and volume of data which is available about public bids. It says that the Government’s Central Digital Platform (“CDP”), which is the hub for information about public procurements, takes an important step towards the goal of building datasets that are fit for purpose. It suggests that the CDP could be extended to require procuring authorities to upload data on unsuccessful bids (without which it will be difficult to assess patterns of collusion between bidders).
The CMA’s ambition for the CDP is likely to face hurdles which may require legislative change (for example, to address the question of how to handle bidders’ commercially sensitive data, and to ensure there are sufficient powers available within the existing statutory scheme). The intention is clearly pointing towards more enforcement at the intersection of public procurements with competition law.
Consequences, for suppliers of public contracts, of competition law infringements
There are serious consequences for breaching competition law. They are potentially wide-ranging and can include significant fines (up to 10% of worldwide turnover), as well as director disqualification and even prison (in the most serious criminal cases).
Suppliers of public contracts should also be aware of the consequences under the exclusion and debarment regimes in the Procurement Act 2023 (the “Act”).
The Act came into force on 24 February 2025 and introduced a new system for excluding suppliers who are involved (or potentially involved) in infringements of competition law. As under the previous law, there are mandatory and discretionary grounds of exclusion. In both cases, the exclusion ground is subject to a “self-cleaning” regime and applies when the circumstances giving rise to the application of the exclusion ground are continuing or likely to occur again.
Competition-related mandatory exclusions
- Where a supplier or connected person has been convicted of the criminal cartel offence under the Enterprise Act 2002.
- Where a supplier or connected person has been found by a decision of the CMA (or other competition regulator), to have infringed competition law by taking part in cartel activity (e.g. bid rigging), in breach of the Chapter I prohibition of the Competition Act 1998.
Competition-related discretionary exclusions
- Where the contracting authority considers that the supplier, or a connected person, has engaged in cartel activity which infringes the Chapter I prohibition, regardless of a CMA (or other regulator) decision, unless immunity from prosecution has been given.
- Where the contracting authority considers that the supplier, or a connected person, has infringed the Chapter II prohibition, or where the CMA (or other competition regulator) has made a decision to that effect.
- Where the contracting authority considers that the supplier or a connected person has engaged in conduct constituting a cartel offence or a substantially similar offence under the law outside of the UK, unless immunity from prosecution has been given.
While it will be a question of fact as to whether a mandatory exclusion ground applies, a contracting authority is required to exercise its judgement in determining whether a discretionary exclusion ground applies. Discretionary exclusion grounds must be applied consistently to all suppliers in the same position.
Contracting authorities are likely to have significantly varying experience and knowledge of the types of behaviours or market practices which are anti-competitive under competition laws.
Perhaps for this reason, in its guidance to authorities on competition-related exclusions, the CMA has set an email helpline for contracting authorities to seek the CMA’s input. The guidance invites contracting authorities to contact the CMA to “ask for more information to assist them in determining whether the discretionary exclusion grounds apply where a supplier is or may be under investigation”.
The breadth of the exclusion grounds
Suppliers should note that the scope of exclusion under the Act covers the wider supply chain. A supplier could be excluded if an exclusion ground applies to any of the following:
- the supplier
- connected persons of the supplier: those individuals and corporate entities with relationships of significant control or influence over the supplier, or those over which the supplier exercises (or has the right to exercise) such control or influence, and
- associated persons of the supplier: those relied on to meet conditions of participation for the relevant tender, except for guarantors. This would, commonly, include some or all of the intended sub-contractors.
Contracting authorities can but are not obliged to check exclusion grounds for all intended sub-contractors. A supplier can also be considered to be an excluded or excludable supplier by virtue of a connected person of a sub-contractor. Every intended sub-contractor must be checked against the debarment list for each procurement.
Both mandatory and discretionary exclusion on competition grounds can apply to equivalent conduct overseas. So (for example) if a court or regulator outside the UK found that a supplier or connected person had participated in a cartel in another country, this could also result in the exclusion of the supplier from bidding for public contracts in the UK.
There is an implied right for a contracting authority to terminate a public contract awarded under the Act, including where the supplier becomes excluded or excludable during the term of the contract.
Debarment
As well as developing the exclusion grounds for competition law infringements, the Act brings in a debarment regime.
Whereas exclusion applies in the context of a contracting authority’s decision to procure a specific contract, debarment has wider consequences. That is because all contracting authorities must now check the debarment list (including in respect of all intended subcontractors) for each procurement. If a supplier is on the debarment list for a mandatory exclusion ground, the contracting authority must exclude the supplier from the procurement.
A supplier will usually remain on the debarment list for up to 5 years from when the relevant event occurred for mandatory exclusion grounds.
Lessons for compliance
The scope for competition law infringement in public procurement is firmly on the CMA's radar. Suppliers will want to revisit their competition compliance programmes and ensure that they understand the relationship between competition law and the procurement rules.
Looking carefully at supply chains and the exclusion status of connected persons, associated persons and sub-contractors is going to be even more important.
In considering the risk of debarment, suppliers should consider our recommended “compliance takeaways” for managing this risk.
The CMA has offered to support contracting authorities to assist them in making decisions on whether to exclude bidders for anti-competitive behaviours.
[View source.]
