The decree, Law No. 51/2026, of August 17, changes how limitation periods are calculated for ongoing competition cases, preventing older lawsuits from being dismissed before a final decision is reached.

The legislation confirms that changes made to Portugal’s competition law in 2022 also apply to cases that are still being considered by the courts, Executive Digest reports.

The change follows the high-profile “banking cartel” case, in which more than a dozen banks were initially found guilty of illegally exchanging commercial information between 2002 and 2013. However, the Lisbon Court of Appeal later ruled that the case had exceeded the legal time limit and could no longer continue.

The disagreement centred on how the limitation period should be calculated. One court ruled that the 2022 competition law applied to the case, while another said the older rules should be used because the alleged offences happened before the law changed.

The new legislation adopts the first interpretation, meaning that certain legal procedures, such as asking the Court of Justice of the European Union for clarification, interrupt the limitation period and prevent cases from expiring while they are still before the courts.

The law originated from a proposal by the Portuguese Communist Party (PCP) following the outcome of the banking cartel case.

It was approved by Parliament in July with support from the PCP, PS, Chega, Livre, BE, PAN and JPP. PSD and CDS-PP voted against the measure, while IL abstained.

Portugal’s Competition Authority welcomed the change, saying it strengthens legal certainty and provides greater clarity over how limitation periods should be applied in ongoing competition cases.