Marco jurídico

Los principios fundamentales de la contratación pública: igualdad, transparencia y proporcionalidad.

¿Qué principios básicos rigen la legislación belga en materia de contratación pública? Igualdad de trato, transparencia, no discriminación, proporcionalidad y competencia.

15 February 2025

Every decision in a public procurement — from the choice of procedure to the award — is tested against a set of fundamental principles. These principles form the legal foundation of the entire procurement law framework and are enshrined in both European and Belgian law. They are not merely theoretical: violations of these principles are the most common reason for successfully challenging an award decision.

The five core principles

1. Equal treatment

The principle of equal treatment requires that all tenderers are given the same opportunities and assessed according to the same rules. The authority may not grant an advantage to one tenderer at the expense of another during the procedure.

In practice, this means:

  • All tenderers receive the same procurement documents and the same answers to questions.
  • The same selection and award criteria are applied identically.
  • If one tenderer is given the chance to supplement a missing document, others in the same situation must be given the same opportunity.
  • The evaluation committee may not use information communicated to only one party.

The Court of Justice of the EU has repeatedly confirmed that the principle of equal treatment is the cornerstone of public procurement law. Even an unintentional unequal treatment can lead to annulment of the award decision.

2. Transparency

Transparency means that the authority acts in an open and predictable manner. The rules of the game must be published in advance and may not be changed during the procedure.

Concretely:

  • The selection and award criteria are stated in the procurement documents, together with their relative weighting or ranking.
  • The authority states reasons for its decisions so that tenderers can verify whether the rules have been correctly applied.
  • Amendments to the procurement documents are published in time and to all tenderers.

Transparency is closely linked to the right to an effective remedy: without reasoning, a tenderer cannot assess whether an appeal is worthwhile.

3. Non-discrimination

The principle of non-discrimination prohibits any form of discrimination on the basis of nationality. This is the European dimension of procurement law: a Belgian authority may not disadvantage a Dutch or French company compared to a Belgian one.

The principle goes further than nationality. The authority may not formulate technical specifications that favour particular products or suppliers, unless this is objectively justified by the subject matter of the contract.

4. Proportionality

The principle of proportionality requires that the authority’s requirements are proportionate to the nature and size of the contract. This concerns both selection requirements and execution conditions.

Examples of disproportionate requirements:

  • A turnover requirement of €10 million for a contract worth €200,000.
  • The requirement of three similar references for a unique or innovative project where such references barely exist.
  • A surety of 10% for a low-risk services contract.

The proportionality principle particularly protects SMEs: excessive requirements unnecessarily exclude smaller companies and restrict competition.

5. Competition

The principle of free competition requires that the authority organises sufficient competition and does not create artificial barriers. The contract may not be written to measure for one particular tenderer.

Practical applications:

  • The authority may not artificially split the contract to remain below publication thresholds.
  • Technical specifications are preferably formulated functionally, not on the basis of a specific brand or product.
  • When referring to a standard, the authority always adds “or equivalent”.
  • Disproportionate deadlines that only one player can meet violate the competition principle.

These principles are enshrined at multiple levels:

European. Article 18 of Directive 2014/24/EU codifies the principles of equal treatment, non-discrimination, transparency and proportionality. The competition principle derives from the TFEU (Treaty on the Functioning of the European Union).

Belgian. Article 4 of the Act of 17 June 2016 replicates the European principles and specifically adds the proportionality principle. Article 5 prohibits the artificial splitting of contracts to circumvent the application of the law.

Constitutional. The equality principle (Articles 10-11 Constitution) and the principle of good governance support the principles from Belgian public law.

Application in practice

When drafting specifications

The principles already play a role when drafting the specifications. Specifications that set disproportionate requirements, contain discriminatory specifications or formulate unclear award criteria are vulnerable to challenge — even before the award.

During evaluation

The evaluation committee must demonstrably apply the same criteria in the same way to all tenders. An evaluation report that insufficiently motivates why tender A scores higher than tender B violates the transparency principle.

At the award decision

The duty to state reasons (Article 29 of the Act) is a direct application of the transparency principle. The unsuccessful tenderer must receive sufficient information to assess whether an appeal is worthwhile.

Common violations

The Council of State has suspended numerous award decisions in recent years due to violations of the fundamental principles. The most common:

  • The application of sub-award criteria not announced in the specifications.
  • Providing additional information to one tenderer not communicated to others.
  • Setting disproportionate selection requirements that exclude SMEs.
  • Changing the weighting coefficients after opening of tenders.
  • An inadequate statement of reasons that does not enable the tenderer to understand the decision.
The fundamental principles are not abstract legal concepts — they are enforceable rights you can rely on. If you spot a violation in specifications (e.g., tailor-made requirements, discriminatory wording, unclear award criteria), ask for clarification through the questions forum. This creates a record of your concern and strengthens a later appeal.
The most litigated violation is **inadequate reasoning** of award decisions. If the authority's explanation is vague, contradicts the stated criteria, or does not explain why you scored lower than the winner, this is grounds for suspension. Request further reasoning within 15 days and carefully compare what the authority says with how it claims to have evaluated tenders.

Sources

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