Homelessness expert Dame Louise Casey has issued a call to arms to tackle the rising tide of homelessness around the world.

Global homelessness has reached new levels, with more than a billion people displaced worldwide.

In England alone, numbers have soared by more than 150% since 2010, with an estimated 4,677 people on the streets each night and 125,000 children without a home.

Dame Louise, who is now chair of the Institute of Global Homelessness, has called on people to get involved in the World’s Big Sleep Out on December 7.

The event, thought to be the largest charitable fundraising campaign in a generation, will take place in up to 50 locations worldwide and aims to raise $50m and help one million homeless people worldwide.

Dame Louise said: ‘I urge everyone who thinks it is unacceptable for any human being to be without a home to get involved.

'In years and decades to come, we could look back on 7 December 2019 as the day when the world decided to end homelessness.

‘We need the public and those in power to act – and act now!

'Please get involved.’

Spearheaded by founder of social enterprise Social Bite, Josh Littlejohn, the sleep out will be led by Will Smith and Dame Helen Mirren telling a bedtime story in New York and London respectively.

London Mayor Sadiq Khan and a host of celebrities have pledged their support.

People are urged to register for an official event or sign up to host their own sleep out, registering at www.bigsleepout.com.

Mr Littlejohn said: I am blown away by the response to The World’s Big Sleep Out so far and incredibly excited to have 50 cities all over the world taking part.

‘By sleeping out for one night on December 7 we can simultaneously express our compassion for homeless people who have no other choice and raise lifesaving funds to make a difference.

'We can also send a message to the world’s political leaders that urgent action is required to address the human suffering that we each witness on our streets every day.’

Dame Helen Mirren added: ‘The World's Big Sleep Out campaign will play an important role in shining the political spotlight on the issues of homelessness and displacement while raising considerable funds to make a big difference.’