"We appeal to those who are eligible and have not yet applied for resident status to do so as soon as possible, otherwise on 1 July they could find themselves in an irregular situation in the country and potentially exposed to a hostile environment," said Pucarinho, at the opening of a briefing via Facebook.
On 30 June, the deadline for the EU Settlement Scheme opened as part of the UK's withdrawal from the EU, through which Europeans can maintain their rights to live, work or study in the UK, expires.
A "hostile environment", explained the diplomat, means losing access to public health services, social benefits and other types of public support or services.
"All Portuguese who have established residence in the UK and who want to continue living here and are not simultaneously British must obtain, or at least apply for, resident status by 30 June", Cristina Pucarinho warned.
According to the Portuguese Government, 375,000 applications have already been made by Portuguese nationals by 31 March, a figure that is higher than the number of national citizens with a UK address on their citizen's card.
However, despite the majority having already done so, the consul warned of the need for everyone to obtain residence status, such as minors or children recently born or adopted.
"We know of families whose parents have obtained status, but have not requested status for their children. They should do so," she stressed.
The system is also open to dependent direct relatives, such as parents or grandchildren, who are outside the UK, or non-EU family members.
The information session, promoted by the consulates general of Portugal in London and Manchester, in cooperation with the Delegation of the European Union, was led by lawyer Chris Desira, specialist in immigration.
The lawyer indirectly addressed the main issue raised in the comments, namely the difficulty to obtain assistance at consulates and renew the citizen card or passport or register children for documents.
The lawyer reiterated the importance that all Portuguese, even those with expired identification documents, apply by 30 June.
"You need to try to get a valid document, but if you can't get it in time, don't wait, make sure you apply by the deadline. It is possible to apply with an expired document by requesting a paper form by calling the Ministry of the Interior," he explained.
He also warned that those with temporary residence permits who have been out of the UK for more than six months due to the Covid-19 pandemic and do not return until 2021 will have to explain their prolonged absence and face a complicated process.