The power of constitutional courts to invalidate elections should be limited to exceptional circumstances and clearly regulated, the Venice Commission says in an urgent report on the cancellation of election results by constitutional courts starting from the cancelation by the Constitutional Court of Romania of the 2024 presidential election in Romania.The report, drawn on the basis of comments by the commission's rapporteurs. was issued on January 27, 2025, pursuant to Article 14a of the Venice Commission's Revised Rules of Procedure.By letter of December 13, 2024, Theodoros Rousopoulos, president of the Parliamentary Assembly of the Council of Europe, requested an urgent report of the Venice Commission on the question: Under which conditions and under which legal standards can a constitutional court invalidate elections, drawing from the recent Romanian case?In its report published on its website on March 18, the Venice Commission makes the following key recommendations:A. Decisions to cancel election results should be taken by the highest electoral body and such decisions should be reviewable by the highest judicial body, the constitutional court or a specialised electoral court when such a judicial body exists;B. The power of constitutional courts to invalidate elections ex officio - if any - should be limited to exceptional circumstances and clearly regulated;C. The cancellation of a part of elections or elections as a whole can be allowed only under very exceptional circumstances as ultima ratio and on the condition that irregularities in the electoral process may have affected the outcome of the vote;D. The decision-making process concerning election results must be accompanied by adequate and sufficient safeguards ensuring, in particular, a fair and objective procedure and a sufficiently reasoned decision based on clearly established facts which prove irregularities that are so significant that they may have influenced the outcome of the election; affected parties must have the opportunity to submit their views and evidence, and the discretion of the judge considering election matters should be guided and limited by conditions set out in the law; decisions must be taken within reasonable time-limits;E. It should be possible to challenge election results based on violations of electoral rights, freedoms and interests by the State, public and private electoral stakeholders, and on influence of the media, and of social media in particular, including those sponsored and financed from abroad;F. States should regulate the consequences of information disorders, cyber-attacks and other digital threats to electoral integrity; candidates and parties must be granted fair and equitable access to online media, and regulations should be implemented to ensure that artificial intelligence systems by internet intermediaries do not favour certain parties or candidates over others;G. The general rules on campaign finance and transparency should be applied to online campaigning using social media platforms; States should also regulate that online electoral advertising must be identified as such and must be transparent, and that social media platforms are required to disclose data on political advertising and their sponsors.