LONDON (AP) — The British government apologized Monday for its "appalling" treatment of some immigrants from the Caribbean, as reports of law-abiding residents being threatened with deportation overshadowed a London meeting of leaders from the 53-nation Commonwealth.

Britain wants to use this week's summit of the alliance of the U.K. and its former colonies to help Britain bolster trade and diplomatic ties around the world after it leaves the European Union. But anger over what many see as the U.K.'s shabby treatment of residents of Caribbean origin eclipsed trade topics.

Members of the "Windrush generation" — named for the ship Empire Windrush, which brought the first big group of post-war Caribbean immigrants to Britain in 1948 — came from what were then British colonies or newly independent states. Those who arrived before 1971 had an automatic right to settle in the U.K.

But some from that generation, especially those who arrived as children on their parents' passports, say they have been denied medical treatment or threatened with deportation because they can't produce papers to prove their status.

The Guardian newspaper has reported on the mistreatment of people such as former House of Commons cook Paulette Wilson, who moved to Britain at age 10. She was sent to an immigration detention center last year after failing to convince authorities she had the right to remain in Britain.

David Lammy, a lawmaker with the opposition Labour Party, demanded answers from the government Monday, calling it "a day of national shame."

Home Secretary Amber Rudd said she was setting up a task force to sort out the Caribbean immigrants' paperwork simply and for free, and promised that no one would be deported.

"We have seen the individual stories, and they have been, some of them, terrible to hear, and that is why I have acted," Rudd said.

"Frankly, some of the ways they have been treated has been wrong, has been appalling and I am sorry," she said.

Prime Minister Theresa May's office said she would meet with her Caribbean counterparts at the Commonwealth summit to discuss the situation.

The British government has taken an increasingly tough line on immigration, which has increased dramatically over the last 10 or 15 years, largely as result of people moving to the U.K. from other EU countries.

A desire to control immigration was a major factor for many voters who supported the 2016 referendum for Britain to leave the EU.

Critics say the British government has, by design or accidentally, taken a hostile attitude to the thousands of people who have made Britain their home.

Barbados High Commissioner Guy Hewitt told the BBC on Monday that he felt Britain was telling people from the Caribbean, "You are no longer welcome."

Some 140 U.K. lawmakers signed a letter urging the government to find an "immediate and effective" response to concerns from Commonwealth-born residents over their immigration status.

The Commonwealth links 2.4 billion people on five continents, from countries such as vast India and wealthy Australia to small island states like Tonga and Vanuatu.

It espouses good governance, economic growth and human rights, but is seen by some as a vestige of the British empire with an uncertain mission in the 21st century.

Queen Elizabeth II, who will formally open the Commonwealth Heads of Government meeting at Buckingham Palace on Thursday, has done much to unite the group. She has visited nearly every Commonwealth nation, often multiple times, during her 66-year reign.

The 91-year-old has given up long-distance travel, so this is likely to be the last Commonwealth summit over which she presides.

Heir to the throne Prince Charles will not automatically succeed her as head of the Commonwealth, which says the choice of its next leader will be a decision for the group.

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