Idris Elba has spoken out against government cuts to housing benefits for 18 to 21-year-olds.
The change, which came in earlier this month, means younger people no longer automatically get the benefits if they're out of work.
The government claims 10,000 people are affected and says it's necessary to save around £65m by 2020.
The actor was speaking at a fundraising gig for the housing and homelessness charity Shelter.
"The government is trying to take away housing allowances from 18 to 21-year-olds," he said
"Seriously man. No one should be homeless.
"It's 2017, there's 850 people here tonight but there's like at least 1,000 men and women on the streets tonight."
Skepta also performed at the event, telling the audience: "This is isn't about any celebrity giving back, this is about us all giving back.
"Everyone should give back, everyone."
There are some exceptions to the changes to Universal Credit payments, including where there's a threat to mental or physical health by living with their parents.
Younger people with children and those in work for six months before making a claim will also be exempt.
In 2015, then Prime Minister David Cameron said the policy would "ensure young people in the benefits system face the same choices as young people who work and who may not be able to afford to leave home".