"We are reaching the conclusion that perhaps ethics is not enough", Marcelo Rebelo de Sousa told Portuguese TV channels RTP and SIC on the sideline of a visit to the country's biggest bookstore.

Rebelo de Sousa has dvocated new legislation to prevent family members being selected for government positions, saying the law in force was almost 20 years old and had not kept up with Portugal's "demanding" public opinion, after a senior Portuguese government official resigned over accusations that he had picked his cousin as his deputy.

President Rebelo de Sousa clarified he was referring to the Administrative Procedure Code, which currently includes an "absolute ban" in nominating close family members, with "bleaker limitations" when it comes to aunts, uncles and cousins.

The President said that if these rules existed for the public administration in general, they should be taken into account for political roles too.

Carlos Martins resigned as secretary of state for the environment last Thursday, a day after his cousin and deputy secretary of state Armindo Alves.