“There are many doubts and fear among the Portuguese community in the United Kingdom," Kirsty Hayes acknowledged in her testimony to committee on European affairs. "The overwhelming majority [of these fears] are not justified.

"The agreement that we reached in December [with the European Commission, in the first phase of the Brexit negotiations] is very broad and offers a lot of security to the Portuguese community in the United Kingdom and to our community here."

According to Hayes, “in practice, any Portuguese citizen who arrives [in the UK] in the implementation period, between 30 March of 2019 [the day after the UK leaves the EU] and 31 December of 2020, will be able to remain under the same conditions, although they will have to register if they opt to stay more than three months."

During the committee session, deputies for the Social Democratic Party, Left Bloc and People's Party expressed concerns about the uncertainties surrounding future relations between the UK and the remaining 27 EU member states, and guarantees of the rights of the some 300,000 Portuguese living in the UK, in situations where they are unemployed or in the case of students or researchers.

The ambassador said that people in those situations “will have the right to request settled status" in the UK, and that the government in London will “reduce to a minimum the documents required” to apply - in response to criticisms about the complexity of the process hitherto, involving a form running to some 80 pages.

In addition, she said, the UK authorities will provide more information on the process in the coming weeks, and officials will be available to help guide people through it.

“This enables the Portuguese community, which is very much appreciated, to stay in the United Kingdom, assuring its rights of residence and access to services," she said.

To gain access to settled status, Hayes said, it is not necessary for someone to be in work - so long as they have lived in the UK for at least five years. If they have not, they can start the process to build up those five years.

All this, she argued, "offers some clarity and security to the community.”

Hayes, who has been heard six times in Portugal's parliament in her time in Lisbon, is to leave the country this summer and be replaced by Chris Sainty.