The Czech Constitutional Court imposed a fine on a lawyer for a poor-quality petition generated by AI
08/07/2026
Disclaimer
The document, the publication of which the Author has given her consent, does not bind under no circumstances the Constitutional Court of the Czech Republic, its Justices, or its employees.
The Czech Constitutional court’s fine on a lawyer for the improper use of AI models, which led to present non-existent case law, raises awarness on the necessity to verify carefully the use of artificial tools, even and especially in proceeding before the Constitutional Court, where legal reasoning and professional care is expected to be at the highest level – avoiding any misleading, complication or delay in the name of speed or time saving (that ultimately brings to the opposite results).
Although the Constitutional Court is authorized by law to impose disciplinary fines to ensure the proper conduct of proceedings, it does not exercise this authority – unlike the general courts – except in rare cases. Throughout its entire history, the Constitutional Court has imposed a disciplinary fine in only four cases.
Already for this reason, the disciplinary fine imposed by this decision attracted attention not only from the expert community, but also from the mass media.
The complainant’s legal representative drafted and submitted to the Constitutional Court, via his attorney’s data box, a constitutional complaint against a ruling of the Supreme Administrative Court. In the constitutional complaint, he cited a total of 12 decisions of the Constitutional Court and the European Court of Human Rights. After carefully reviewing the constitutional complaint, the Constitutional Court found that a substantial portion of these decisions did not exist at all, and that the respondent had grossly misinterpreted some of them.
Pursuant to Section 61(1) of the Constitutional Court Act, if a party grossly obstructs the proceedings, the presiding judge of the panel – when the panel is deciding the case – may, by order, impose a disciplinary fine of up to 100 000 CZK (approx. 4 123 EUR).
The Constitutional Court emphasized that the purpose of mandatory legal representation in proceedings before the Constitutional Court is to ensure that communication with the Constitutional Court takes place at an appropriate formal and substantive level. Mandatory legal representation is intended to protect complainants from suffering procedural harm due to a lack of knowledge of constitutional law or inexperience with proceedings before the Constitutional Court. Communication with the Constitutional Court cannot take place at an appropriate formal and substantive level if the complainants’ legal representatives were to unreasonably burden the Constitutional Court with submissions in which they rely on non-existent legal sources.
The Constitutional Court examined in detail the arguments contained in the seemingly flawless constitutional complaint. It carefully verified whether the decisions cited by the legal representative in his arguments actually existed. It also considered the possibility that the cited decisions might contain typographical errors in their case numbers. In addition, the Constitutional Court devoted considerable effort to verifying whether certain assertions in the constitutional complaint were or were not supported by the case law cited by the legal representative.
The Constitutional Court found that some of the cited decisions did not exist at all, some had been grossly misinterpreted by the legal representative, and only a small portion could have been relevant to the complainant’s case. The number and nature of these defects reliably refuted the claim that they were merely isolated typos or other clerical errors. Beyond what has been mentioned, the constitutional complaint – in addition to relying on non-existent legal sources – showed certain signs of the use of artificial intelligence (anglicisms, incomplete, clipped sentences, inconsistent citation formatting, failure to distinguish between a judgment on the merits and a procedural ruling). This led the Constitutional Court to conclude that the legal representative had generated the submission using one of several artificial intelligence models but had subsequently failed to verify the existence of the cited decisions and the accuracy of the argumentation.
It is important to emphasize that, for the Constitutional Court, it is generally irrelevant which individuals or tools attorneys use to draft submissions to the court. However, as professionals experienced in the law, they assume full responsibility for the submissions and are therefore also accountable for any delusional arguments generated by artificial intelligence, if it was used in drafting the submission.
The Justices concluded that the legal representative misled the Constitutional Court and thereby unnecessarily complicated and delayed its proceedings. By the manner in which he drafted the petition on behalf of his client, he thus grossly impeded the proceedings before the Constitutional Court.
The Constitutional Court, thus, imposed a disciplinary fine on the legal representative as the liable party because he was the author of the submission, even though it constituted a procedural act on the part of the complainant. At the same time, the Constitutional Court sent the complainant, through his legal representative, a request to correct the constitutional complaint so that the complainant would not suffer any procedural prejudice as a result of his legal representative’s conduct.
With regard to the amount of the fine imposed, the Constitutional Court decided to impose only one-quarter of the legally permissible range. This is because the legal representative had committed a gross obstruction of the proceedings before the Constitutional Court for the first time, and the defect could still be corrected.

