VIDEO: World Down's Syndrome Day clip backed by James Corden and pop star Christina Perri goes viral

Mum-and-daughter duos Rachel and Amelia Blencowe and Melissa and Francesca Lockwood appear in the clip released to raise awareness of World Down’s Syndrome Day tomorrow (Wednesday).

The “50 Mums, 50 Kids, 1 Extra Chromosome” video features 50 parent-and-child pairs lip-synching and signing to Christina Perri’s ballad A Thousand Years.

Christina Perri and James Corden, star of the popular Carpool Karaoke segments on The Late Late Show in the USA, threw their weight behind it:

Rachel, who was invited on ITV show This Morning today to talk about the video’s surprise success, said: “It’s nice to be raising awareness of children with Down’s in a positive way.”

The 34-year-old mum, of Whitworth Lane, Manvers (pictured above), added: “It’s unbelievable how big it’s become.”

Rachel and Melissa are both members of a Facebook group for parents of children with Down’s Syndrome who were born in 2013 and 2014 and are now aged three or four.

Melissa, of Goldfinch Court, Manvers (pictured below), said: “We never thought people would get behind it the way they have — it’s been brilliant.”