A forecast issued by Shelter on Wednesday suggested 131,269 youngsters across Britain will spend the season without a permanent roof over their head.
Alastair Welford, the founder of Nicodemus, a Christian charity in Warwickshire which supports young people affected by issues including homelessness, said the figure could be an underestimate.
He told Premier: "I can quite believe it, in fact, if I'm honest, I question that figure, I question whether it's accurate.
"To me, that number, I would say, is possibly [too] low, if anything."
The stat includes an expected 9,500 kids who will spend their Christmas in a hostel or bed and breakfast - as well as others who will be in emergency accommodation provided by local authorities.
Shelter found London was the place worst-affected by child homeless, with the borough of Westminster experiencing the highest rates in the country.
Urging more churches to help tackle homelessness, Alastair Welford added: "When you think of the number of churches in this country, if 20 per cent of those started little homeless projects - little marginalised youth projects with some support [from us], it would be incredible.
"What a great witness as well."
Angel found it tough to deal with the rats and mice while living in a hostel. It's no place for a child.
— Shelter (@Shelter) December 5, 2018
If we act now, we can change tomorrow for thousands of families facing homelessness. #donatetodaychangetomorrow https://t.co/lUmZMbRUIt pic.twitter.com/WtAOE6ZqdF
Heather Wheeler, the minister for homelessness, said the Government is providing £1.2 billion to tackle all forms of homelessness "but we know we have more to do".
She added: "No family should be left without a roof over their head, especially during the winter months, and we are working to ensure all children have a safe place to stay where they can thrive.
"Councils have a duty to provide temporary accommodation for families with nowhere to go, and we have been clear that they also have a duty to prevent homelessness in the first place."
Click here to listen to Premier's Alex Williams speaking with Alastair Welford from the Nicodemus charity:
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