The bill’s sponsor revealed on X, formerly Twitter, that the law, which came into force on 23 November, involved no legislative brainstorming but was produced after 15 seconds from a command of around 250 characters.

Porto Alegre councilman Ramiro Rosário told The Washington Post that the prompt was: “Create a municipal law for the city of Porto Alegre, originating from the legislature and not the executive, which prohibits the Municipal Water and Sewage Department from charging the owner of the property for the payment of a new water meter when it is stolen.”

Its response “astounded” Mr Rosário.

He said it suggested a 30-day deadline for the city to replace stolen water meters and a provision waiving water bills if the deadline was not met. All 36 members of the council approved the response, which they were unaware was generated by AI.

Mr Rosário said: “I support the idea that artificial intelligence can help optimise resources and the time of political agents and public servants, allowing them to focus on what is truly essential for their work.”