Helen Mirren sleeps rough in London

Helen Mirren has joined a sleepout in London to highlight the plight of homeless people.
Helen Mirren has joined a sleepout in London to highlight the plight of homeless people.

Oscar-winning British actress Helen Mirren has hit out against the "exponential rise in homelessness" as she prepares to sleep out in central London as part of a global charity appeal to fight the scourge.

Mirren joined Hollywood stars Will Smith and Brian Cox and an estimated 50,000 people in the "World's Big Sleep Out" event, which takes place in more than 50 cities from New York to Delhi and raises funds for homeless causes.

"What's disturbing, profoundly, to me is the exponential rise in homelessness that I've noticed ... in every city in Los Angeles, in New York, in London," she told the Thomson Reuters Foundation.

"The line between having a home and homelessness for many families is so thin," she said, before reading a 'bedtime story' to more than 2,000 people assembled in bright orange sleeping bags in London's iconic Trafalgar Square.

Homelessness has been increasing in England for nearly a decade amid rising rents, a freeze on welfare benefits and a social housing shortage.

"There are thousands of people sleeping on our streets ... and tens of thousands of families - including 135,000 children - trapped in temporary accommodation," said Polly Neate, head of British homelessness charity Shelter, who called the crisis a "national emergency".

Most European countries have also seen a rise in homelessness in the past decade, fuelled by fallout from the global financial crisis and an influx of international migrants.

Mirren said she hoped to raise awareness of the global scourge and make people feel less "helpless".

"You can't deny it, it's there in front of you, in front of all of us," she said. "The problem is becoming much too big."

Australian Associated Press