According to a note from the office of the minister for environment, João Pedro Matos Fernandes, the resignation request was made from Costa Rica, where Martins was “representing the Portuguese government”.

In the letter, Martins justified his request with the fact that this controversy could harm the executive and the Socialist Party (PS).

“I believe that the matter may harm the government, the Socialist Party and the prime minister. With the same honour that determined my acceptance of governing duties, I request my resignation to the prime minister and the minister”, he said.

Alves' resignation over accusations of nepotism was reported by online newspaper Observador and confirmed to Lusa by a source from the Ministry of the Environment.

Alves asked to resign as soon as he found out about the news, according to the same source.

After the controversy, the government’s source told Lusa that Fernandes only became aware of the family ties between Martins and Alves on Tuesday.

This situation comes amid controversy regarding alleged family ties in Portugal's government from the opposition ahead of a general election in October.