"With more and more immigrants arriving, the work of legalisation is essential,” she said at the end of a conference in Lisbon to mark 30 years of the Convention on the Rights of the Child and 40 years of UNICEF in Portugal.

She argued that by simplifying the legalisation process it would be possible to stop people going through a long transitional period between arriving in the country and being legalised.

"This work to simplify visas and the teaching of Portuguese are two fundamental conditions for the integration of immigrants and are our priorities,” she stressed in a statement to journalists at the end of a speech in which she argued that it was fundamental to regulate migratory flows.

Mariana Vieira da Silva argued that the measure is necessary for families and the economic development of the country.

In a previous speech, the ombudsman, Lúcia Amaral, warned of the difficulties faced by immigrants from other continents, namely Asia, due to the language barrier, delays in being processed by Social Security and the Foreigners and Borders Service, as well as the conditions in which citizens who enter the country irregularly, sometimes accompanied by children, are held at airports.