LONDON (AP) — Activists seeking compensation for Black people whose right to live in Britain came under question expressed disgust and disappointment Tuesday after they were blocked from freely attending the governing Conservative Party's annual conference despite being accredited for the event.

Anthony Brown of the group Windrush Defenders said he was denied unfettered access to the conference in Manchester unless he agreed to be escorted by one of Prime Minister Boris Johnson’s advisers. Another campaigner who works with families affected by what has become known as the Windrush scandal was allowed in Sunday but not Monday.

Both were accredited to attend the event after paying a 225-pound ($307) fee each for the chance to network with delegates from around the country and to lobby for their cause, Brown said.

Brown said he briefly entered the conference hall on Monday after being met by a member of Johnson’s staff who insisted on accompanying him. He said he left after about an hour when it became clear the aide was “trying to manage the whole situation.’’

“I can’t figure out why I would be such a problem to the party machine. Why would a couple of people who want to talk about the Windrush scandal be such a problem?'' he said. “We shouldn’t be surprised when we’ve seen such disgusting headlines about grandmothers being detained and not getting compensation.’’

The Windrush scandal has rocked Britain since 2018, when the Guardian newspaper and other local media published reports about the troubles of long-term legal residents from the Caribbean who were caught up in a crackdown on illegal immigration starting several years earlier.

Thousands lost jobs, homes and the right to free medical care, many because they arrived as children and couldn’t produce paperwork proving their right to live in the U.K. Some were detained, and an unknown number were deported to countries they barely remembered.

The scandal draws its name from the Windrush generation of immigrants who came to Britain from its former colonies to help rebuild the country after World War II. The Empire Windrush was the ship that brought the first large group of migrants from the Caribbean to Britain.

The government has apologized for the treatment of Windrush immigrants and set up a program to compensate victims of the scandal. But activists have criticized authorities for moving too slowly and are demanding that the government pass legislation that recognizes their rights to citizenship.

Parliament’s Public Accounts Committee earlier this year said the compensation program was overly complex and too slow in handling claims.

Brown said campaigners are seeking to have the compensation program declared unfit for purpose at a High Court hearing set for Nov. 18. He thinks that might have influenced the Conservative Party's actions at the conference.

The party did not respond to requests for comment.