As a young poet, Silveira was one of the most prominent critics of the literary elite in Cape Verde.
He was associated with the views of the Claridade group, and argued in favour of an African cultural identity of the islands.
In Uppsala he had close links with the South Africa Committee of the city, which was crucial for the initiation of solidarity work for the African Party for the Independence of Guinea and Cape Verde (PAIGC) in Sweden.
According to the PAIGC, his dismissal was a disciplinary action due to Silveira's failure to attend a meeting in Guinea-Conakry.
[10] Silveira later worked for the United Nations, representing the U.N. in countries like Somalia, Angola and Mozambique.